i have a 2010 and my friend Sanju (Checkmate screenname) has 2011. he had the old software and i had the new.
His max was 335whp and mine is 358whp. Both cars have no mods at all so we assume the software has at least about a 15whp impact.
BMW M3 E92 - Silverstone II
BPM Sport Stage II Tune + Test Pipes, GTS DCT Tune