BrenR has QS4s with M3s, I believe. There was a thread a few days ago where Bren said "QS4s match my M3s perfectly", Ken said "they don't match my M50s that accurately" and the conversation generally went to he** after that.

Guys, can you try again ? Nicely this time ?

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8