Apex XTX50 and XTX40 - which first stage to choose?

[buddhasummer]

"2) replaceable high pressure orifice vs its being part of the reg body."

I use FSRs because of this. The only Apeks first stage with replaceable crown, why? No idea. By the way, should you damage the crown in any other model, it's a pretty penny to replace the body.

 

[buddhasummer]

...And I don't need a turret and do like 2 hp ports.

 

[grf88]

The DS4 body is about $90USD in Europe so I guess you have to weigh the odds and compare to the difference in cost. I have several pretty old DS4's and there is no problems with the crown.

 

[Scuba Client]

The UST is the unsealed version. There is also a different version, the DST, that is sealed. In oother words, if you want a sealed regulator of that style, you can get it. So that doesn’t have to be a distinguishing feature of the FSR.

Personally, I prefer sealed regulators, not just because of cold water, but mainly because of it. If you’re never going to dive in water below, say, 10°C, it’s not a requirement, but it does keep silt and salt out of the inside of your regulator, which for me is a good idea.

The performance of the UST/DST will be just fine for you. Over balance, not over balance, heat exchangers, finish, etc.: those are all marketing things. With the type of diving you have described, you will not be able to tell the difference.

In my opinion, the difference comes down to two things: cost, and hose routing/flexibility (from the turret). If you do not see doubles and serious overhead training in your future within at least five years, then it doesn’t matter. If you do, then the turret has the advantage of allowing better hose routing and less strain on your hose in a long hose/restriction regulator donation situation.

ETA: The UST/DST and FSR both have two high-pressure ports, so I’m not sure what would make a difference there.

Do you consider the O-ring on the turret (DST) to be a weak point at depth? I've seen the Scubapro MK25 O-ring on the turret and it's sturdy.

 

[shurite7]

Do you consider the O-ring on the turret (DST) to be a weak point at depth? I've seen the Scubapro MK25 O-ring on the turret and it's sturdy.

I’ve service both the Mk25 and DST and the o-rings on the DST are fine.

Not too long ago I serviced a DST and found a shredded o-ring inside. Before taking apart regs I check the MP/IP and inhalation of the second stages. In this case the first stage was fine and it didn’t leak. A part of the o-ring was found in the AirSource second LP hose.

 

[Scuba Client]

Not for nothing, my personal set of regulators are clones of the DST.

So what brand of clones are you suggesting?

 

[Scuba Client]

I’ve service both the Mk25 and DST and the o-rings on the DST are fine.

Not too long ago I serviced a DST and found a shredded o-ring inside. Before taking apart regs I check the MP/IP and inhalation of the second stages. In this case the first stage was fine and it didn’t leak. A part of the o-ring was found in the AirSource second LP hose.

Would you recommend the TEK3 or (ATX100, in which Apeks has discontinued production)?

 

[diver42]

I bought a DST in 2000. It was my first reg for single-tank diving. When I moved to doubles, I bought another. Now it’s one of my stage regs for cave diving. Every few years, I have it serviced. The turret is helpful in single tanks and in stages. It’s also sealed. (I have a UST for my argon rig. It works.)

Contrary to some advice, I would buy the reg you want to have for the next few decades. Treated well, they last. Decades ago, people worried about the reliability of the turret. No more. It lasts.

 

[Centrals]

For a single tank diver with conventional secondary donate (i.e. “octo”), I doubt that there would be any real difference in hose routing at all, for any of the Apeks firsts. The only time it comes into play is in very different configurations: when you are using manifolded doubles (which require hoses to crisscross oddly), with long hose donate (the out of air diver goes in front of you which creates a nasty and risky 180 degree bend, alleviated by the swivel turret), or side mount (which is kind of both problems combined! ).

If you are never going to be anything but a conventional single tank diver (and by “never“ read “in the next five years”), then my recommendation would be to either buy the cheapest one; the environmentally sealed one; or the one with the replaceable orifice, depending on other details of your diving or tolerance for technician servicing risk.

Not for nothing, my personal set of regulators are clones of the DST. I am a back mount doubles diver with long hose who dives in 1°C water, so the combination of swivel and environmental sealing are the best for me.

1. I have not noticed the OP was asking twin set diving.
2. I am a cert. trimix diver since late 90s and have been using only Apeks a yr or two earlier and DST was one of those. There is NO need for anyone to lecture me on the routing of DST in twin set even with the 5th port. I use the DST on one of the deco tank because of the turret.
3. I am more interested on the OP's question rather than your style of diving.

 

[Centrals]

Would you recommend the TEK3 or (ATX100, in which Apeks has discontinued production)?

TEK3 was a sick joke. The routing was horrible.
FST used to be the flagship for Apeks and then came FSR. No reason to be around for so long. I believe the late John Bennett was using it for the 308m dive 20yrs ago. RIP.
I never have any issue with the turret O-ring on DST.

If anyone noticed Aepks reg could not lock on the IP and suspect the orifice is damaged. Before throwing it away or take it to the shop for an expensive repair. Buy a new pencil with eraser at one end, insert the eraser end to the orifice and gently rotate it with minimum pressure. It might work wonder. But if the orifice is corroded then......
Apeks also has a special polishing tool for that.
Make sure no salt water ever get into the HP chamber and my 20+ yrs old DS4 is a good testament to that. If in doubt, give it an immediate service, preferably DIY, it is dead easy for Apeks.