I have used a set of these for armature level racing an they worked great. Finding a 150 size rear was hard to do but conti and Bridgeston 003's are what I run. I am a mid pack club racer and I thought worked great. Tire life was also good I though considering they lasted about 3 track days.
I would buy them again if you prefer to stick with the 150 rear. If you want bigger I'd try the Michelin race tires. Assuming you don't ride street