I use VU a lot, since DC hipped me to its use in a 0 VU = -8 dBFSD context. "Virtually Useless" has become, as he put it, "Very Useful." No need to have it set to 0 VU = - 14 dBFSD. CDs would peg the needle every transient, that way. But at -8, it almost never pegs and the forte ball park is spot-on for pro masters of this (loud) Era.
Also, I use a DK Audio MSD-100 with the very useful stereo vectorscope. It's like a LissaJous, but vertical, instead of angular. Yes, many times the line is off to one side or other, but when you are hearing a passage that sounds like it's supposed to be centered and yet isn't, you can dial in a very thin line of correlation between channels and verify (with ears) that this is correct or not. For tape reproducer azimuth adjustments, it's super precise and allows for quick work.
Yes, it's just a reassurance, but that's our line, after all. Reassurance that all is well.
I also use SpectraFoo if something sounds weird and I want demonstrable proof. I tried using it for eq guidance, but I found that I was chasing my own tail. We aren't trying to generate pink noise, folks. Mostly, it's for checking the noise floor. As it is, I can't see how I could possibly benefit from balanced power (in my present setup). The noise floor of the analog chain is well below the quietest signal I am concerned about. The chassis and some circuits are grounded to the cold water pipe via copper bus bar and solid core 12 AWG copper wire. Pin 1 is also lifted on each input that doesn't specify not to (float it).
Andrew