Scubapro MK25 EVO / S620Ti Review: Breathes Like It Owes You Money

I've had the MK25 EVO / S620Ti on my primary rig for a while now, mostly off Jupiter and out of Riviera Beach, plus a handful of travel trips where it lived in a roller bag and got abused. This is the reg a lot of South Florida divemasters end up on, and after enough weekends behind it I understand why. It also has a couple of honest tradeoffs that nobody mentions when they're handing you the box.

What it is

The MK25 EVO is an air-balanced, flow-through piston first stage. In plain terms: the piston is the only moving part doing the regulating, water never touches the spring chamber the way it would on an unsealed piston, and the design moves an enormous volume of air with very little intermediate-pressure drop as your tank empties or as you go deeper. Scubapro's anti-freeze / anti-contamination protection on the EVO is their XTIS (Extended Thermal Insulating System) — an internal sealing approach that keeps the ambient chamber dry and insulated rather than the dry-sealed diaphragm route other brands take.

It comes in DIN or yoke, and the port layout is generous: multiple high-pressure ports and a swivel turret of low-pressure ports, so hose routing for a long-hose primary, a necklaced backup, an inflator, and a drysuit hose is never a fight. That matters more than people think once you're actually building a rig.

The S620Ti is the second stage: pneumatically balanced, with titanium accents in the cover and valve mechanism, an adjustable inhalation knob, and a dive/pre-dive (venturi) switch. It's light, it's compact, and it's tuned to take advantage of all the air the MK25 is willing to hand it.

What it does well

The headline is the breathe, and it earns it. This thing delivers air like there's no resistance at all. On a fast descent at Jupiter, dropping past 90 feet into a current with a scooter or just kicking hard against the drift, you ask for a big breath and it's simply there — no lag, no leaning into the demand valve. The combination of the high-flow piston feeding a balanced second stage is genuinely effortless, and that's the part everyone who's tried one remembers.

A few things I've come to rely on:

• Consistency as the tank drains. Air-balanced piston means the breathe at 500 psi feels basically like the breathe at 3000 psi. On a long Blue Heron Bridge dive where I'm sucking a tank down to the bone hunting critters, that consistency is real.
• Depth stability. No noticeable change in cracking effort whether I'm at the bridge in 18 feet or down on a Jupiter ledge at 100+. It just doesn't care.
• The adjustment actually works. The inhalation knob and venturi switch on the S620Ti aren't cosmetic. I run it dialed open and venturi forward when I want the free-flowing feel, and I'll snug the knob down and flip to pre-dive when I'm doing a giant stride into chop or staging at the surface, which kills the tendency to free-flow.
• Travel weight. The titanium second stage is light, the first stage is compact, and the whole package packs small. For a Bahamas or Cozumel trip where every pound in the bag counts, this is a warm-water travel reg that doesn't punish you.

For the diving most people on this coast actually do — recreational depths, warm water, occasional travel — it's hard to out-breathe and easy to live with.

Where it falls short

Here's the part I want to be straight about, because the marketing won't be.

It's a piston design, and piston designs have a personality. The flow-through piston is what gives you that incredible breathe, but the piston is also the part that rides in the ambient chamber. XTIS does a real job of keeping water and contaminants out and insulating against cold — but a sealed piston is still not the same thing as a fully isolated diaphragm. In genuinely cold water, the cold-water story here is weaker than a dedicated diaphragm reg, and Scubapro themselves position the EVO carefully for cold environments. For Florida water this is a non-issue 99% of the time. If your future includes ice, quarries in February, or deep cold thermoclines on a regular basis, weigh that honestly.

Silt and grit. Any piston that breathes this freely is, by nature, moving a lot through a precise mechanism. I'm careful never to set the first stage down in the sand at the bridge, never to leave the dust cap off near a dirty deck, and to be religious about rinsing. That's good practice with any reg, but I treat it as non-optional with this one.

It free-flows if you're lazy with it. A high-flow balanced second stage tuned for an easy breathe will sing on the surface in wind or on a giant stride if you've left it wide open. The pre-dive switch exists for exactly this reason. Use it. Not a flaw, just a thing you have to actually do.

Price and the service story. It sits at the premium end, and I'm not going to invent a number for you because street pricing moves and depends on the package. The bigger asterisk is service. Scubapro's warranty and free-parts-style program is tied to buying from an authorized dealer and to keeping up with the prescribed annual service at a Scubapro dealer. That's great if you have a good local shop and you're disciplined about annuals. It's worth less if you buy gray-market online or you're the type who skips a year — read the current terms before you assume "valued for life" applies to you, because the conditions are real.

Compared to the Apeks XTX200

This is the comparison that actually matters, because it's a philosophy difference, not a quality difference. Both are excellent. They're built for different priorities.

The Apeks XTX200 is an over-balanced diaphragm first stage. Diaphragm designs seal the internals away from the water completely and are the traditional choice for cold-water and technical diving — Apeks built its reputation on regs that shrug off cold and silt because the mechanism never sees the environment. The XTX200 second stage is rugged, easily serviceable, and tuned to be a workhorse. If I were diving cold quarries, doing a lot of overhead, or wanted the most environmentally tolerant, overbuilt-for-abuse option, the Apeks is the smarter pick.

The MK25 EVO / S620Ti trades that cold-water overbuild for the lightest, freest-breathing high-flow feel in the category. The piston moves more air with less effort, and in warm water that's a tangible, every-dive advantage. For South Florida recreational and travel diving, I'd take the Scubapro for the breathe and the pack weight. For cold and overhead, I'd lean Apeks for the diaphragm's environmental isolation.

Put simply: Apeks diaphragm = sealed, cold-tolerant, overbuilt. Scubapro piston = higher flow, lighter, easier breathe in warm water. Neither is "better." They're optimized for different dives.

Who should buy this

Buy the MK25 EVO / S620Ti if you're a warm-water and travel diver who wants the easiest, most effortless breathe you can get and you have a trustworthy authorized Scubapro dealer nearby to keep the service program intact. For weekend diving off Jupiter and Riviera Beach, the bridge, the ledges, the occasional liveaboard, it's close to ideal and it's the reg I keep choosing.

Think twice if your real future is cold water, ice, or serious overhead, or if you're going to buy gray-market and skip annual service — in those cases a sealed-diaphragm reg like the Apeks XTX200 will serve you better and the Scubapro's biggest strengths won't pay off for you.

Verdict: for warm-water rec and travel, this is a buy. It breathes like nothing else in the price class, it travels light, and the tradeoffs — piston cold-water ceiling, dealer-tied service, a free-flow tendency if you ignore the switch — are all manageable and all honest. Go in knowing them and you'll love it.