Hope this thread is not too old to revive.
OP, thanks for your give-back. It so happens that I am in nearly the same (original) situation as you. My 2011 E93 with 19s is an IS though, but I think the suspension is the same as the M-Sport setup in the 335 non-IS?
Anyway, my oem RFT (Potenza RE050) are shot at 6500 (yes 65 hundred) miles (rears), fronts are ok and I know that is expected, to wear faster than fronts, but seriously, 6500 miles?). Probably for the best as they are hard riding. Yes I know, it's a performance car, yada yada, but I am kinda ready for a softer ride to and from work and would give up some sharpness for that. From all I've read, DWS is that tire. (I used to work from home but now commute 45 miles a day, and what was ok for a weekend toy is not ok for a DD.) I LOVE the car though and can't imagine getting anything else that compares, especially now that BMW has sissyfied the 3 series.
Now, I would like to upsize the tires to 245/35 in front and 265/30 rear. This should not pose a problem according to people at DTD I've talked to, but it does increase the sidewall height slightly, putting more rubber between me and the road, which should translate to a bit more comfort.
So what is the question? Well, just that I've read that the DWS may feel too mushy? I have actually driven DWS before, for a week on my old G35 before I traded it in for this car, and my daughter's Golf. In both cars I experienced this 'slowness' of turning that was not disagreeable, just different and something to get used to. But this car is in a different league, so am still doing my homework.
No tracking or racing btw. Only the occasional tire squeal (can't call it a burnout). Thanks for listening guys, would love to read your opinions.