My 335xi JB+ @ 100% on 93 octane (JB4 map 2 on 93 octane ran almost the exact same)
0-60: 4.2 seconds (Vbox)
1/4 mile: 12.5 @ 110 (track)
I've raced a 2012 5.0, from a launch it wasn't fair as my AWD jumped hard, the 335xi falls on it's face after 90mph though which is where the stock 5.0 will start to pull it.
A stock 5.0 vs a 335i JB+ @ 100% on 93+ octane is pretty evenly matched IMO.
Cobb/JB4/Vishnu tune with some good fuel or even a bit of E85 mix and things change big time. 335i's will trap 115-120 tune only on great fuel with decent temps.