Silent Running makes a good point. It appears with CCR diving it's all about equipment. The CCR dier, er diver, is so focused on "what his body is doing", or maybe "what's it doing to my body", that attention is siphoned from the important subject at hand, the underwater world.
My buddy is a typical diver. Last month, on the first dive of the day, he forgot to set his computer for NITROX (he was diving 36%). That cut things short, ya know what I mean.
The week before, I went into the water with an empty tank. Post mortem of the tank showed a bad valve seat. In my defense, I did set the computer.
These are mere foibles. Now, I'm thinking, what's the odds of diving with a CCR rig that requires a check list, getting it right, or not, and surviving it. Hmmm.
I like technical stuff. My boat is equipped with electronic gadgets, I mix and pump NITROX, I do lots of technical stuff. Everything I own has a manual about 50 pages long. How long is the manual for the CCR? 200 pages? Well, as a rec diver with an appreciation for various complicated toys, I might be a natural rebreather diver. Yet, it may just be that my life is complicated enough, and that's just on weekends.