it depends on the voice. the 835 is better for me. on 2 of the guys in my band, the 58s are better. and on another one of the guys, neither works well--an ev 357 is the ticket for him.
I have always used an Audix OM2 for live vocals. One of my bandmates has a Senn e835, and he has had nothing but problems. Maybe he just got a crappy one.
I found the e835 to be too bright/sibilant on my voice (baritone) for most stuff. It required too much corrective EQ to make it sound ok. I use an SM57 with a windscreen for live stuff.