I only use CERPPCs (the others are too weak) and then only when long range battle is anticipated, particularly at night. I also rarely use them in combination with other weapon types unless the other weapons all have identical travel times to each other. Trying to balance 3+ different lead times is very unwieldly.
So with all those caveats in place I use only a couple of the dev made PPC variants, most notably the 4 CERPPC Novacat, but I also will pull out Cougar B in the early game occasionally, and Scat C rarely. Now you said "my" variants so I don't know if you meant when mechlab was built. In that case I would probably not build many or any smaller PPC mechs since chasing after highly mobile light mechs is inefficient in the early game, and I would err towards lasers or CQB weapons. A 100 ton PPC wielding monstrosity for when I hit Khan might be a possibility I suppose but I don't think I'd be able to pull off 6 CERPPCs no matter how many heatsinks I strapped to my ride.
I voted 10%. I don't use and wouldn't make many variants with PPC's, but I do get a fair amound of mileage out of the 4 CERPPC Novacat.