Atomic M1 vs. Scubapro MK25/S600

[FZJ80]

Simple question. Which is better?

I have the opportunity to purchase either of these regs at just above cost. I know they are both piston firsts, but that the M1 is a sealed design. Besides that, I don't know much. Let me know what you think. If you can't give me a head to head comparison just let me know your experiences with what you have. Thanks.

 

[scubatoys]

Simple question. Which is better?

I have the opportunity to purchase either of these regs at just above cost. I know they are both piston firsts, but that the M1 is a sealed design. Besides that, I don't know much. Let me know what you think. If you can't give me a head to head comparison just let me know your experiences with what you have. Thanks.

If you want the anti freeze... go M1... otherwise, I'd be torn to do the B2 to get the swivel. But overall, any of them are great. It's just personal preference. but basically, you're choosing between a lexus and an infinity here... either choice will be right.

 

[FZJ80]

So many people with opinions and nobody but Larry is willing to share. Sad...

 

[dlndavid]

So many people with opinions and nobody but Larry is willing to share. Sad...

I dive with the Scubapro MK25/S600. It is the only reg I have ever used to any extent.
So not much of an opinion which is better.

 

[Lane Zimmer]

I can give you my experiences with both. Each have their inherent advantages and disadvantages.

The M1 1st stage is built similar to the older Scubapro MK10. It's a very reliable design, proven over many years. The second stage is also built similar to the Scubapro's. They breathe great in all conditions. The engineers who designed them were ex-Scubapro guys. The main disadvantage to the M1 is the way the 1st stage is sealed. They filled the ambien pressure chamber with Christolube and closed it off with a rubber baffle. This does 2 things. 1) Everytime the reg is pressured up, it squirts out a small amount of Christolube. Having used one as a stage reg, it gets messy after a while. 2) Christolube is expensive. The amount of lube required to fill the chamber drives up the cost of service. If that doesn't bother you, then it's a fine reg.

The MK25/S600 is also built similarly to the M1. The MK25 is not sealed, so there's no mess nor any lube to replace. However, the MK25 has a tendency to have high pitch squeals. The way the HP seat is designed, combined with inadequate lubrication if the stem oring, causes a harmonic squeak. Otherwise, it's is very reliable. The S600 second uses a plastic air barrel, which makes the reg lighter and more corrosion resistant than a metal one.

Given my choice between the two, I would take the MK25/S600 over the M1.

 

[Doc Intrepid]

If your profile was filled out, we'd be able to make some guesses as to the average water temps in your area. My experience is with SP Mk-10s, 20's, and 25's. I cannot compare these to the Atomic regs, but as stated previously, both are high quality products.

At depths between 150 and 200 fsw the pair of Mk-20s that I'm using currently perform extraordinarily well - and I've used them under some arduous conditions.

If you're diving in extremely cold water you might want the additional 'anti-freeze' quality provided in the Atomics M1. If you're diving in more temperate water, however, I can only observe that I've recently had the chance to compare my SP regs to both Apeks and Oceanic 1st stages, and I'm very pleased with the performance of the SP regs. FWIW. YMMV.

 

[Kestrell]

I have an M. It is great. However the SP Mk25/600 is great too. If you need cold get the M1; otherwise get whichever one looks cooler to you.

 

[wmspdi]

I had a MK25/S600 and a 2 MK25/X650s. I wasn't all that impressed with the X650. As mentioned earlier in this thread it whistled, and would slightly free flow in some positions. When I joined my sheriff departments dive team and found out many of our dives would be in "black water" and or very cold water I decided to get a sealed first stage. I didn't like the MK16 so knocked it off of the list of possible regs.

While on a PADI specialty training dive I had an opertunity to try one of the instructor's Atomic M1 rigs. The next day I purchased one to use the following weekend. After 2 dives with the M1 I sold both of the X650s (main & back-up), and the S600 (my teenage son's reg) and replaced them with 2 M1s (1st,2nd & octos) and a B2 (1st/2nd) with an SS1 Titanium octo/inflator. In my case the sealed first stages were the selling point. When I get out of the water I have to clean a lot worse crap off of my gear than Christolube. Usually we have a fire fighter standing by with a pumper truck waiting to hose us, and the gear, down before we remove our exposure suits.

The 2 year time schedule for overhaul was a big plus (after getting the last annual service invoice for three SP regulators at $75.00 each). Also the fact that Atomic doesn't hold you to an annual service schedule to keep your warranty in force was important. I service regs when they need it, not based on the calander, or the LDS need to generate service income. FOR ME Atomic was the best choice. If you've got the big bucks go for the Ti2.

 

[jnb2b1]

Have used both regs, Scubapro MK25/S600 is a fine reg but the M1 breath like a dream.
You can run 80% o2 out of the box. It breathes the same at 300 as at 50. Good bless America Harley and Atomic (cars suck but who’s counting)

 

[Rick Inman]

If you want the anti freeze... go M1...

...get whichever one looks cooler to you.

I got the M1 'cause Larry talked me into it.