I'll have to test drive one. I have an e92 M3 as well, in addition to having owned 4 different TTV8 N63 (1 DINAN flashed) F Series cars, I wouldn't categorize my X3 35i slow, quite the contrary, based on butt Dyno and other factors. Perhaps I have a factory freak N55.
The Motortrend test results you posted are the slowest I have seen for the 35i. Anyway enjoy that SQ5 nice ride no-doubt