I love the clearance limits used in abundance in the USA. Tell me what time, place and altitude limits you want me to conform with and I can let the 'puter (or the knoggin) handle the rest. Takes some load off ATC and puts it in the cockpit in regions where cockpit workloads are generally not that high anyway. When ATC start radar vectoring (necessary at times, I know) I feel like I'm back learning how to fly IFR and chasing localiser needles.