I have some spare VANOS Solenoids that have seen less than 100 miles.
I had an error code and rough idle so swapped the old set out to this set (Aftermarket), code went, car drove fine though rough idle remained.
So I bought BMW ones today and zero change in drive or idle. Decided to keep the BMW ones as I can't return them and they are OEM.
In short: bought this set for £100 and I've noticed no difference between these and OEM BMW ones for £200.