I'm sure you figure for the 120 steel is probably correct, but I had a BC failure when wearing a LP 120 steel tank and wearing near zero buoyant exposure protection. I ended up quite negative at 160 feet and opted to just swim up and it was more strenuous than I liked. It left a big impression on me about being "extra heavy" and having nothing to ditch. Incidentally, I had another total BC failure this weekend - with the OP assembly popping off.
Yep, that's why I've been asking about "being comfortable w/o ditchable weight. Sorry for diverting the OP's thread there... - I only had an air bladder failure that must have occurred during transport and I noticed it when rinsing out the inside of the bladder after 2 weeks of warm (salt) water diving (last year). So no in water failure - yet -...
Anyway, following that I practiced a little with emptying out all air out of the BCD (but then it was colder fresh water and I was in a 5mil (all I got right now, need warmer gear...) + vest & hood & gloves and socks... and trying to ascend w/o any extra lift (and still 3/5 gas in an AL-80 and the Al 40 pony full of course).... didn't really like it that much... I could do it. I was only at 40 ... 45 feet... Ended up hanging pretty heavy on the skinny sausage string sausage during the safety stop (w/o kicking...) Did it, but was not comfortable with that all that much... and thought there are reasons to carry either ditch-able weight or a reliable means of redundant lift... Wondered how I would have fared trying that from 130 feet (some day I'll know) ... I sure will need to wrap my mind more around that and practice more (ha, or buy a dry-suit...) before I know where I stand... but that's why I've been asking about "comfort w/o ditch-able weight and w/o redundant wing...".
I sure am not experienced enough to make my final call on that yet (no kidding, not even owning a BP&W, just looking into it and only having used them (with double 120HPs) for 3 days so far... . Had no extra weight then either... - but did have a redundant bladder (manual inflate for that). And I am sure wondering how way more experienced divers think and feel about this... (no matter how differing those thoughts might be)...