I have a phobia of computers controlling things for me (maybe I have seen terminator too many times

) but there is just something about the inspiration I don't like (well a few things actually)
IF I were to go the rebreather route, first choice would be the Halcyon semi closed, completely mechanical, if it goes wrong then you know about it. Fully closed I would go for a KISS, but a guy I know has just got a Meg, and that is quite nice looking.
Only problem with the Halcyon is no PP02 monitor, but then again, you just plug in the correct gas for the depth, so not much different to switching gas on OC, just got to pick the right one. I could only really see this being an issue on ascent/descent, so I would fit a normal PPO2 monitor, or could just fit a simple little HUD.
And your right about the bailout thing. Halcyon and kiss both have built in bailout mouthpiece, but it is certainly the cylinder size thing that is an issue. Saw a diver going of to the moldavia and his bailout was 3lt pony with 02. HMMM, lets see, 50m, 100% O2, that gives us errrm, oh bugger maths, 6 Bar PPO2 :head