I never used modified cams.. but a fella I know had a Piper Fast Road cam in his Ford Escort XR3i (it was a while ago
) and that was jolly splendid..
As you can tell, Piper have been in the cam-shafts game for a very long time. They'll be good quality for sure.
Just make sure that you don't go for a too-weird profile though.. I think people can be too ambitious in their choice of cam-shafts.. some of the extreme profiles only make sense over 6000rpm.. but people buy them anyway (lured by all that additional BHP they'll get) and then whinge about how useless the cam is..