Very interesting thread. The posts show a lot of interesting points about rebreather divers' habits and phylosophy. I think it could even serve as a preface for a course textbook.
That said, here is my stone to the edifice: Of course it'll be biased as, apart from a few hours of try dives on eCCRs, I chose to dive mCCRs exclusively.
1) mCCR breeds good habits. Yes, yes, yes. But not only that. I think mCCR is the only way to really make your awareness grow and develop: Awareness for yourself (mind, senses and body), awareness for the smooth functionning of the life support apparatus you have on your back and awareness for your environment (pressure, temperature, movement).
2) Only those who dives CCRs with a leaky valve can talk about diving while manually running the unit. To me, manually driving PO2 with an on/off system is like driving an automatic car while shifting the lever as if driving a stick. Can be done, gives you a feel for the real thing, but it's far from the rewards of it.
Sure it will take some time to tune in everything down to the last percentile of efficiency on a mCCR. But a) the learning is beneficial; b) you still enjoy diving during this period of time and c) it's such a reward when you're there.
I must say that now I do not touch my O2 MAV more than 2-3 times during a dive, plus once at each stop/ascent. Again, leeds to awareness.
3) Obsolescence of Kiss CCR. Compared to what ? No manufacturer on the market has come close to match the beautifull simplicity of it. Of course I'm willing to admit that I am biased here. But I will also certainly admit that a CK is not a good plateforme to be used as a eCCR or even hCCR. Been there, done that. Born as mCCR, it must be used that way.
4) It is my opinion that eCCRs drive the manufacturers towards more complexicity. In my books, the only exception is JJ.
For the others, under the false pretense of safety and simplicity (read make it easier for the diver to run the unit), you can see units with canbus, 5 to 6 cells, 2 solenoids, crazy flashing leds, activated mouthpiece and what not.... For me, these can stay in the military area or the deep diving industry where they (or the technology) were born. They have nothing to do on a sport or tek dive boat. Don't get me wrong, I accept technology, but one must be aware of the differences. After all, we still have sattelites over our heads running smooth on Penthium chips. But I digress here.
What I mean here is that at the end of the day, I still want to decide if I want to dive, not let the computer do it for me. Technology can assit me, not take over.
5) Task loading on ascent and mCCRs ? BS in my books. If you've got too much on your plate during ascent when diving in conditions that are usual in your area, you should probably not be there. Or not alone, and you should plan/organize your dive in such a manner that you can get assistance if need be. Again awareness (feel, sense, listen) is emphasized during that part of the dive. Prioritize, sort things out. Take your time to ascend. Basic prerequisites that eCCRs tends to push to the side.
6) eCCRs are great when you're working underwater: video, photo, search and recovery..... But this is not sport or tek diving, this is work.
I acknowledge my post has an opinionated tone but I told beforehand that I was biased.
Having said that, I just bought an eCCR head for one of my M units in order to try and run it as a hCCR rig. Go figure ! I guess when considering the KISS acronym, you don't want to get stuck in the Stupid part of it. And I'm considering photo, so there will be a use for it (or so he says to the misus who asks what was this check for).
Best
Philippe
