Thats backwards. TRS can (and will) short the signal wires to each other or to ground while plugging in, which is bad because it causes pops. XLR doesn't do this /me goes off to look at wiki ...

This is exactly what happens, by the way, when you plug a 1/4" TS (unbalanced) jack into one of the mixer's "bal/unbal" TRS inputs: Your unbalanced source "hot" goes to XLR pin 2, and your ...