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I did this on my F10, both with my summer and winter tires. Summer I use 275/35-20 (27.6") and winter 245/45-19 (27.7"). Stock staggered 20" were about 1" smaller diameter.
Benefits:
Fills the wheel well, looks better
Less lowering needed to eliminate fender gap
More sidewall = better ride, more wheel protection
Benefits F10:
Corrects* inaccurate speedometer (reads LOW from factory)
Corrects for optimistic fuel economy computer
Drawbacks F10:
Can cause minor rubbing on front on large compressions, especially lowered (not a big deal, use careful setup with coilovers)
4% slower in-gear acceleration (cannot feel difference), but no change in trap speed in 1/4 mile
The speedometer in the F10 reads about 3% over actual with the factory tire size, and is about 1% under actual with the 1" larger sizes. My car is now travelling about 101 km/h when I set the cruise to 100. Verified with GPS and roadside radar speed indicators.
My wife's E90 was 8% over from the factory, so upsizing her tires 1" (4% again) just got it closer, but not quite there. Yes, even with oversized tires her car still only travels 96 km/h with the speedo set to 100. Which is good, because she's driving 140 all the time.
Here's my car with oversized tires, lowered, and one pic with winters on stock suspension in the driveway:
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