I've only looked at the Submatix but haven't tried it yet.
My impression was pretty good though, the build quality seemed on par with other production rebreathers. Layout and hose routig is clean, I liked the clear bags and cannister that lets you have a look at the moisture level between dives. WOB is supposedly quite good for a unit with backmounted CL, good enough to pass CE testing. The Submatic is also very streamlined.
Having one bag inside the other could turn into a problem when there's a leak between them, causing CO2 buildup. The case is also larger than the Sport Kiss' and more restrictive. The size comes into play when travelling as well when choosing tanks at you location. I don't know what the final sensor solution is, but the unit wasn't designed to house tripple sensors from the start and thus everything I've seen so far has a rather homebuild look to it. Nor do I know what the final wiring/monitor looks like, again from what I've seen that has always had the conversion look to it.
The Sport Kiss is hands down the easiest rebreather to (dis-)assemble and maintain, the quality of manufacture is very good. With the one exception being the hose weights which look decidedly low rent, like the heavy weight version of bailing wire. The metal boxes protect the guts very well, and the shape mirrors that of most carry-on bags. Hence it works well for travel. The option of alu or ss allows you to choose depending on your weight needs. The box also gives some flexibilty regarding tanks, several sizes of 2 and 3 ltr tanks will work. If you go with the ss case and use camstraps larger tanks should be an option, too. You won't run into the "it almost fits" situation quite as easily as on a rig with internal tanks. The scrubber is the easiest granular scrubber to pack properly I've tried. WOB is pretty good for rear CL. Being able to easily adjust the volume is a great feature. The O2 sensors, while not the "standard" R22D, are well placed and easily accessible. Jetsam offers the option of replacing one display with a cable ready to integrate a dive computer. Or Shearwater Research offers one that will replace one display with a deco computer that reads all three cells, giving you dual readouts for two of them. The stock setup has individual cables connecting the three sensors to three displays that have their own power supply. That's redundancy. I also like the simplicity of the KISS valve, it works and works well. The Sport Kiss also has the BOV rather than just a DSV which I consider a good safety feature.
Not much on the downside other than the before mentioned hose weights with their agricultural look. Mind you, they work, but look like they came off a farm tractor. Some sort of a handle would be nice to have, both for lifting and protecting the connector pods. If you want clean hose routing you'll need to buy a bunch of swivels, I got them from M&J. Those three items are easily fixed though.
No independent testing done on the unit yet, something that always bugs me. The factory's depth limit will likely limit your ability to take CCR trimix training in the future.
I doubt Submatix can offer better customer service than Jetsam, but if they can match it you would be in very good hands indeed. Having a local dealer/distributor for parts (and service if needed) is very convenient, but with Jetsam's customer care that is not an issue to worry about when owning a Kiss rebreather.
Finally the price, I don't think the units are far apart in their respctive countries, but you will have to see how much of a difference there is between buying within the Commonwealth vs buying within the EC.
I choose the Sport Kiss and am very happy with that decision.
