A comparison between controllers? Really a hard thing to do.
London airspace surely is different to Amsterdams. Efficency in an upper airspace center is way easier to achieve than in a terminal area, isnīt it?
However, a real good controller is the one that does not kill my pax and me, and prevents me from doing so. That might be in a super busy circuit or airspace or a remote tower in the middle of nowhere.
All the extras like directs etc. are nice to have, no doubt, but are just that.
Having said that, I really enjoy flying in EHAM from time to time. Most accomodating guys them Dutch, even if I hate their camping cars on MY Autobahn.
Swing into 22? No prob mate. Can we get 27 instead of 18R? Yeah sure, turn now...and some guys humor is just cracking...