To be honest I tend to just go with the speed everyone else is doing, that varies all the way from nothing to about 85.. I don't care for being the one that's getting hurtled past but I'm very rarely the one hassling to get past someone either.
I'm also one of those nutcases that is prepared to use the "slow" lane if there's nothing else on the road.
Frankly I wish the police would spend more time enforcing the lane hogging rules than enforcing (especially on the motorway) speed limits that were set before airbags, ABS, stability control and brakes that weren't made out of cheese.
But hey.. common sense.. who needs that.