I only saw the "real" (discuss!) YES (Benoit David & Geoff Downes line up on the Fly From Here tour) once but that performance is immortalized by Squire's utter stage dominance (in a pleasant, non-Ted-Nugent-way
), general gung-ho attitude, devil-may-care
gifted sloppiness and, errrr ... V O L U M E !!! He was a force of nature. I can't remember any other band where a non lead-vocalist bass player held the whole band (in the case of YES not exactly consisting of slouches and shrinking violets) so much in his grip. That said, he sang so much, he was really a second lead vocalist.
I also saw the "other" (discuss even more!) YES aka ARW quite recently and Lee Pomeroy played
all the right notes skillfully on his lefty Ric, but he wasn't in any way leading the band like Squire had. The difference (from a bass player's view) was profound, Chris Squire's occasional bum notes or not! He was - may the eternal bass gods (un)rest his soul - a real Ric-Rambo. If sometimes in his mother's wardrobe.