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 :-)
Current: 2016 F10 535i xDrive AW w/ Black Dakota, ZMM, ZCW, ZDA, ZDB, ZPP, 688 & Black Grills + Euro Headlight Switch, Euro Tail Lights, Euro Side Mirrors, Euro Warning Triangle, Euro First Aid Kit, M5 Spoiler, M-Performance Style Front Lip
Retired: 2011 E92 M3 -AW
....ED April 29th, 2010
Retired: 2007 E92 335i -Space Gray.....ED Oct 19th, 2006