I don't think I'd want to have all of that extra stuff on my face. I already go to MAV's for dil and O2 addition, I don't necessarily think that having that on my face would be any easier than it already is. It's an interesting concept, but MAV's are pretty well tried and true. I'm curious to see how the longevity of the Divesoft unit plays out. I'm not sure there are enough out there with a ton of hours on them like the other options on the market. It will be interesting to see if there are any issues that pop up once they get some miles on them.
Where does the O2 add go? Exhale side? Inhale side? I'd be wary if it was putting O2 straight into the loop without some time to circulate. Could be squirrely if it stuck on.
One of the reasons I don't like the rEvo is because of the ADV. On the unit I try-dived it was practically useless. Coupled with no ability to shut it down, it just gave me the wiggles. The Meg plunger was annoying, but functional, the SF2 and Pelagian pretty much just take me thinking that I need to add dil and it happens.
My SF2 is a DSV only. It will get a Shrimp eventually. My Pelagian has it's own little BOV. My Meg had a DSV, put a Shrimp on it, never went back. I'm a fan of the BOV and don't find scootering or long dives with it to be annoying. I don't like flippy DSV/BOV's, I'm a turny turny kinda guy (hence the Shrimp and not the ISC BOV on my Meg), and the stiffness of the Divesoft I played with put me off. I like an ADV I can shut off, don't mind MAV's on my chest, and unless I'm diving backgas bailout (pair of LP50's) my BOV is plumbed offboard via QC6. 3L onboard is dil and inflation only. Way too small an amount to trust as bailout for a deep dive. LP50's it's not an issue. I've got more gas than most people carry as first bailout anyway.
Typically in a cave, I'm sidemounting two bailouts, and any other gas gets dropped. Left side is bungee'd, right side has long hose for donation. It's the same gas because I don't trust a single bailout to be my only source in the event of a serious CO2 hit. In Mexico, that's usually just two tins of 32%, with 50% and O2 if there's some deco planned, those get dropped.