FWF.As always, the FCTM is your guide on these and many other issues with respect to HOW to fly your aircraft.In an ideal world we would all rotate at the correct rate, but many factors can interfere with this.The key element is to know the tailstrike pitch attitude and be wary of this during all takeoffs, but the situation you are describing , under rotation, has two immediate effects, namely a reduced climb gradient, at least initially, and secondly a higher speed than ideal during the early departure.A good way to counter act this is to remind yourself, on each and every departure, ideally just before you line up, what your TARGET speed is.For most takeoffs V2 plus 15-20 for all engines operating and V2 plus 5 with an engine out, will give you very very close to the optimum climb performance.I suggest you start doing this now and dont stop doing it until you retire from flying.Pete.