Production Division (not "class"!) representation for May matches in Eastern Colorado:
AGC 21/59 (36%)
PPPS 18/58 (31%)
Rocky Mountain 300 31/133 (23%) (60+ rounds per stage and people still shot Production!)
PSAC 19/54 (35%)
CCPS 15/51 (29%)
BRC 10/63 (16%)
Your area may vary. Here, it feels well-represented. I shot Production most of 2009 and always had someone on my squad I could compete with. In fact there were (and are) enough B-class Production shooters to have a fun little rivalry