When I bought my R it never really ran that well.
It felt strong but would stutter and hesitate at the higher end of the rev range.
The first think I did was give it a full service, changed all lubs, plugs, points, leads, cap, arm, fuel filter, air filter... the lot. It still hesitated.
The full service was not a waisted exersise though because I now know the exact condition of my lubs and feel that I can drive the car in anger in the knowledge that everything is somewhat pretected with fresh, good quality fluids.
When I changed the knock sensor, it was like a new car. Smooth and responsive.
I do not drive my car often on the road. Usually gets driven when I'm off to the track or getting work done on it. I've probably had it out about 10 times since I bought it one year ago and covered 1500mls. I've just renewed my insurance and will give it another MOT and tax and hopefully there will be some group gatherings next year but my primary use for this car will be track.