What 2nd has beat the G250?

[rsingler]

Love my Deep6 Signatures! They have nice strong alignment bosses inside the case, so you won't twist the barrel reattaching a hose (hello, Apeks MTX-R? Hello, HOG?).
The performance is fantastic, and the performance for cost is out of this world!
That said, like the venerable G250, it doesn't have a microadjust, but at least the service manual lets you shim the poppet spring as the reg ages. It's really a non-issue, unless you want to experiment with your cracking effort all the time. That's where a microadjust is fun.
It may not be a 40-year reg, if only because the faceplate is so pretty. Far nicer than the butt ugly G250 faceplate (except @Nemrod 's creations), but the decorative plate may take a few hits over the years.
My only substantive comment is a plus/minus thing. The Signature turbine poppet is a HUGE safety advantage. It doesn't matter what position it's in, it will never disengage from the lever feet. Ask my buddy who got fired from his shop after one of his service repairs on a standard reg had a lever disengage and the customer wanted to sue after he went "OOA" with a full tank. Yeah, technician mistake, but still...
But because the turbine poppet is not fixed in position, the circle of orifice imprint can rotate subtly over time. The only thing that means is that it may come out of tune slightly. But since the tuning instructions are in the service manual available to any owner, the fix is pretty straightforward. I'll take the safety advantage any day.

 

[Nemrod]

My "crreations," well, yes I did hydrodip a few G250 covers and not only are they tough as nails but the finish can be repaired. However, Scubapro circa 1986 offered four custom, hand painted covers for the G200/G250 and each was unique. The four were the Surf, Mardi Gras, Webs and Safari. Here is the Mardi Gras G250 that I traded to a friend for his daughter who loves pink stuff:



I like pink stuff too so I hated let it go . And this is a Scubapro genuine Surf:



Uh, lesson in fisheye lens distortion, notice how much larger the G250 Surf looks compared to the necklaced G250 slightly further from the lens. Also, I am quite beautiful or handsome or whatever and those fisheye lenses just do not do me justice, ha, ha . Just saying .

 

[Tracy]

How about other brands?

Apeks XTX50 -
Pro's: microadjust
Con's: everything else. Lousy barrel retention - easy to twist out of vertical. Flimsy case. Poor purge valve excursion. Average flows/venturi augmentation on testing, as the whole competing Venturi design has no vane at all, but instead just a disrupter roof over the gas exit hole

If you are going against a G250, at least compare the reg that made Apeks what it is.
The TX50
Still a two finger barrel retention but they were stout fingers and you almost had to try and snap them off.
The case was similar to g250, they don't break
Con was the plastic wear plate on the diaphragm was the wrong material and would bend over time making it so you couldn't tune it without replacing the diaphragm.

 

[Geo7]

I can't help but taking a (biased) look at which regs the guy who designed the G250 (Dean Garraffa) designed next after the G250, and, more importantly, what he felt needed changing. It shows a nice evolution:

G250: Milestone, gold standard. High performing, balanced 2nd stage made of plastic and with adjustable venturi.

G500: a) smaller, and b) seat saver.

G500 mk2: a) still as small, b) still seat saver, c) microadjuster.

Atomic T1, a) as small as G500, b) simpler seat saver, c) microadjuster, d) elliptic exhaust diaphragm for better WOB while keeping case geometry fault minimal, e) no corrosion thanks to titanium, and f) interchangeable exhaust Ts.

Of course, that evolution might not be worth much to someone who feels the G250 breathes better for them. There are subjective aspects as well.

 

[lowwall]

Mares Epic -
Pro's: Aux gas pathway adjacent to valve orifice virtually eliminates lever freezing; new barrel design eliminates the need to bend the lever legs for removal during service; above average gas flow
Con's: A shade mouth heavy; average Venturi augmentation at high gas flow; no improved exhaust WOB over older designs; barrel retention controlled by a single thin plastic clip.

That's the wrong Mares second stage. You either want the all-metal Atlas Adj or the lighter and cheaper plastic - excuse me "technopolymer" - Dual Adj (aka XR HR).

Both of these eliminate the Epic's gimmicky plastic "Twin Power system" pseudo dive/predive switch.

Regarding your cons.

A shade mouth heavy - The Epic is all-metal and thus heavy at 329g. The Atlas Adj is also metal, but slightly lighter at 313g. Plastic wins here, as the Dual Adj is only 185g,

average Venturi augmentation at high gas flow - I'm not sure where this comes from. I have the opposite problem. BTW, it's technically not a Venturi system at all. The VAD tube delivers all the gas into the mouthpiece extension on the reg body. This results in relatively lower pressure in the main body of the reg which pulls the diaphragm inward. WOB typically goes negative once it cracks and gas rushes in to the point where you can't really "sip" gas from Mares second stages. Also thanks to the VAD tube, the gas pathway is both unimpeded and large in diameter which again should contribute to being able to handle high gas flows. What am I missing here?

One con that wasn't mentioned is the VAD assist isn't adjustable or blockage. If you inhale, you get the assist.

no improved exhaust WOB over older designs - I didn't realize this was a problem. FWIW, the current generation of Mares seconds do have a different exhaust valve and tee than the Abyss generation. I like the exhale though, unlike the inhale I can meter out the exhale as slowly as I want.

barrel retention controlled by a single thin plastic clip - This is valid. But it works in shear so should be strong enough. It does allows for easy servicing. Finally, the clip is easily replaceable and is included in the service kit so you don't need to worry about long term plastic degradation. Unless you never service it. In which case, you should consider a classic Mares downstream second like the Abyss or Prestige/Rover.

IMO, the VAD bypass tube really is a superior solution compared to similar types, whether it be the Abyss versus the Conshelf (1085) for a downstream design or the Atlas or Dual Adj versus comparable barrel seconds.

 

[Nemrod]

Unfortunately the Atomics have a soft face plate that has been known to deteriorate and they have an auto seat saver that at least for me I do not want nor the auto Venturi control. But they do breath as nice or nicer, good regs, just not trading a G250 for one. And the Atomic cover cannot be removed without tools or without purchasing an accessory kit from Atomic.

!!!!!!But Atomics do have a titanium barrel!!!!!!! in some models!

The G series regulators are plastic, yes, but it is glass fiber reinforced polyamide which can take a serious hit without damage. Unlike brass, it can take a hit, deform and then return to shape. Of course if you hit anything hard enough it can be broken. What other company aside from Scubapro uses fiber reinforced case materials?

 

[bretski]

No argument there. If you don't do side by side testing, ANY well tuned second stage can feel just great! But look what @bretski said after his comparison. It's like a brown bag wine tasting - subtle differences come out, that can grow to bug you once you focus on them.

THIS.

I was hyped about the S620Ti, and I wanted it to become my "best ever" second stage. After 3 days of diving it 4-5 times per day, I started focusing on those subtle things. I had planned to swap between it and the G260 regardless, but at the end of a dive when I looked at 6 divers surrounding the RIB waiting to get out of the water, I decided to clip off the S620Ti and putz around with the G260 that was on my necklace.

"Ahhhhhhhh, this is nice."

Dove the G260 for the rest of the trip, and barely noticed it, other than a little bit of torquing on the mouthpiece, but that was a hose issue. Fixed that on the next dive with a spare hose that I brought along. (Side note to @rsingler, the 48" was a great idea to throw in the gear bag).

Without the "other bottle of wine" to try, I would have been perfectly content with the S620Ti. It's a very fine reg. I'm not getting rid of it. I'll let my son (who is a newer diver) try it out, and if he loves it, I'll let him keep it.

However, for me, the G260 was simply better.

 

[BoltSnap]

Unfortunately the Atomics have a soft face plate that has been known to deteriorate

That happened about twenty years ago. Atomic promptly corrected it, and it hasn't been an issue since.

 

[Jake 10]

I will go with the G250V, S620Ti, C370

 

[Geo7]

That happened about twenty years ago. Atomic promptly corrected it, and it hasn't been an issue since.

+1: Yes, this affected only T1, Z1 generations. Ti2 front covers made recently don't rot, nor the others.

Also, the front cover can be removed easily by hand. There used to be a diaphragm retaining ring that needed a tool if it was torqued hard. The new ones come apart by hand easily. Unlike the Apeks XTX50 examples that passed through my hands: impossible to remove the front cover, and in a tech focussed reg no less...