I have both a 335i and an M3 and I daily drive both. My 335i is a modded 2010 n54 e92 6AT 335 (Procede, meth, dps, LSD, coils, wheels/tires) and my M3 is a 2013 e92 ZCP DCT M3.
For daily driving, I would say that the M3 looks great and is much more comfortable than my 335i but that's it...otherwise the 335 is much better in that regard.
The 335 is a rocket at any speed and at any RPM. And it gets 25 mpg in mixed driving. The M3 has to be wound up to go fast and even driving it easy I get 15 mpg. Both are fully-loaded with NAV, Premium, upgraded stereo and so it's almost like driving the same car except when you step on the gas.
I drive the M3 more because it's new to me and I'm trying to put more miles on it. I want to break it in nicely before I put my blower and exhaust on. Maybe after those are installed I will have a different opinion. But currently modded 335i > stock M3 for daily duties.
Daily: 2013 e92 M3 MW FR DCT ZCP / ESS VT2 650 S/C, Akrapovic Evolution, ST BBK w/ drilled rotors
Track/Airstrip: 2011 997.2 Turbo S PDK / GIAC tune (9 second file), Champion Intercoolers, BBi exhaust / Ohlins coils+LCAs+endlinks
Beater: 2013 X5 3.5sport