Talk to Jason Caldwell about his thoughts on flood recovery a few years since changing to CCR.
I come from a GUE C1 background and picked the rEvo with full RMS for a number of reasons including it being nice and thin to fit through caves.
Everyone throws in the arguement about flood recovery but is it really such a big deal in actual practice - not many full floods out there that I could find.
You also have the benefit of Damo being in Melbourne with full spares and service on your doorstep.
One of the biggest ticks on my list being down here in Australia is No Head to send back!!
If a controller dies in a remote area then it can be dived on the dreams in manual.
Flood recovery is not as important to me now as it was when I made my original list because since getting instruction, I have taken on the mantra that my unit has two modes:
1. It works and I stay on it
2. It doesn't and I am bailed out - if I choose to go back to it in the shallows for deco, then I may choose to do that.
I've let water in my loop a couple of times - early days in error at the end of a dive, but since doing hypoxic trimix, I've decided now that I never remove my loop while on the surface; let's discuss the dive on the boat and my buddies all know that. Mainly due to the possibility of breathing hypoxic gas from the BOV on the surface, so if I always use the same procedure, there is less likelihood of this happening.
I let a little bit of water in my loop while diving quite a lot as I look from side to side, so it's nice to be able to expel that out via the counterlung dump. I tend to hold the mouthpiece quite loosely in my mouth it seems and I never get jaw fatigue - longest dive on the unit has been 3 hours 40 mins.
I also have a GUE background as most know and it was the clear thinking in Clare Pooley's original post that made me ditch the Satori PSCR in favor of CCR. It is interesting that GUE have now adopted the JJ and courses have been running to train their Tech2 divers on the unit - with their config of course.
My unit has been rock solid and I've never had to send my head back, but know of guys that have. Jan seems to turn them around quite quickly and does other little free upgrades for people too

I'd rather have the guy who designed and built my unit carry out repairs than a service agent, so have no issue with sending it back if I ever had to. Jan doesn't seem to charge for return freight either, which is nice. Most of the guys that have had an issue have had the issue with the HUD, but that has now been resolved it seems. The Shearwater controllers seem to be very reliable and I haven't heard of one faulting on a JJ yet. I think the DiveCAN version of the JJ should be interesting and should offer the redundancy that Gareth is looking for.
My choice not to buy the rEvo was not solely based on flood recovery or lack thereof. I still would not buy one now. I lot of guys like them and think they are a good unit, but I prefer the flexibility/simplicity of the JJ and potted electronics. No unit is perfect, not the JJ, Meg, Inspo or rEvo. I think the JJ is let down in the USA by no local representation, but that is about to change it seems. Support in Australia is pretty good really with Barry and Rob Main now teaching on the unit and both guys keeping stock of spares. Bazza has a spare head to loan his customers too, which is nice. Truth be told, I would be more likely to buy a Meg or an Inspo than the rEvo. I like the ability to be able to be in any position I want to be to get that perfect photographic angle, head down, head up, on your back - the JJ breathes well and I don't have to worry about flooding cells if I've let a little water in my unit. The JJ water traps and protection system are very simple and well engineered designs from the Tee piece in the exhale counterlung to the scrubber/scrubber can, leaving the diver and the unit well protected. I like doing tests, so I put some fresh water in the bottom of my can one day at home to see how easy it was to flood the cells (cells removed of course and used sorb) and it was nearly impossible to get water on the cells. The only way was to be on my back and then go head first from the on your back position. When taking pictures, I'm more likely to go head up if on my back than head down. The scrubber can is the second water trap too, so it has to make it past the first one in the exhale counterlung.
In tight caves, I've found the biggest issue is having full bailout cylinders hanging down below you, not the height of the unit on your back. I think the GUE system with Lola valves, flex manifold and twin 7's with a small oxygen bottle and suit inflation bottle is the perfect combination for caves as it reduces the amount of bailouts you need to carry below you. I'll have a play around with it over the next few months.