Re: Any f30/f32 n20 running on thrum or supersprint exhaust?
If you pick 987903 (centre resonated pipe) + 987906 (rear muffler with quad pipes) there's no drone, it's quite comfortable but with a nice sportier tone.
Actually you could go for the centre pipe 987913 without much of a drone issue unless you have a very sensitive hearing and/or have childreen in the back often. If it's an automatic it tends to keep the revs at less than 2600 rpm all the time, so I would recommend the resonated section.
No difference in terms of performance with the twin on the left, the quad or the dual (for 335i diffuser), we tested them all.