Testbed

These days I generally go for big test beds generated by BedMaker. Like right now, my main test bed (when working on APS) is 100 random bots that Diamond scores <= 80% against. Your test bed sounds well put together to me - improving against problem bots is good, and having a diverse set of other bots helps to ensure you're improving in general instead of just specializing against a different set of bots.