The main issue that I have is when I am playing live (which is often... particularly at WSOP over the next 2 months), nothing is doing the math for me. I have to not only figure my own stack in BB, I have to figure the pots, my bets,
other people's stacks, etc. So when I'm playing on ACR, I will occasionally click over to the BB display just to check something and then switch it back. Keeps me in the habit of doing the math myself. (It helps that my PokerTracker4 HUD has the player's stack BB in it by default.)
But that said, it
is a little disturbing to realize that your stack size has shrunk considerably
in terms of BB even though you need an abacus to count your chips. (And I keep my stacks like a freakin' cash drawer so it's easy to count.) I have had many a point where I have thought, "I'm in great shape! I still have well over 125,000 chips... wait, crap. That's only 16bb?!?" It's all relative to the current blind level, so we need to be able to constantly shift our perspective as the game changes.