Owned both.... When E92 335's first came out, they were beautiful, fast and cool. I still like them very much but it is in no shape, way or form better / faster than an M3.
But then I am among those people who overpaid $25K for a slower version of 335 -what do I know :-)
Retired: 2011 E92 M3 AW w/ Silver Novillo ZCP, ZTP, ZPP, 494, 6FL, 507, 302 & 415.....ED April 29th, 2010
Retired: 2007 E92 335i -Space Gray, Black Leatherette + Alum, Nav, ZCW, ZSP, PDC, CA & Sunshade.....ED Oct 19th, 2006