I absolutely love all the retro clones, semi-clones, simulacra and related games. They a ll produce little bits and pieces I can use. The profusion of choices and expression of similar rules and themes gives me lot's of fodder to play FRP the way I awlays have. I've always been what I would call and omnivorous DM taking a bit from here and a bit from there and making a game of my own in essence.
I'm sure I played a "pure" version of a rule set now and again over the years but in the main I've never been a purist. Sometimes it's been adapting a feature of another game system (or a related setting), other times I grafted on a segment of rules perhaps replacing a related rule in the main game and finally there were times when I took two or more games and bashed them together into a new game for my group to play. I've played AD&D with RuneQuest-2 strike ranks, D&D with TFT talents, curiously enough D&D has always been the core.
I'll admit it here for a time I loved the D20 days, there was a delightful smorgasbord of rules to grab from. At one point I shoved together Arcana Unearthed, Conan and Everquest d20 into the D20 game I played for about a year. I did however feel the weight of the rules and the damaging inertia of players not willing to read a few hundred page rulebook in order to learn how to play well. I whipped up my own D20-lite and it was good.
The OSR games drew me back...sort of, I never really left and I played BFRPG for a while in one of the few campaigns where I used a tone of modules. An old school system and a few other compatible rule systems were all that was required to run a fun campaign using Wilderlands (necro-d20 and original JG), B2 (old D&D), Castyle Zagyg (cnc).Temple of Elemental Evil (AD&D), Castle Greyhawk(AD&D2), Undermountain(AD&D2),Whiterock(d20) and Rappan Athuak(d20) which required constant rules adaptation. The rules were never stale.
So I'm clearly rambling here but I just love the current environment with a multitude of compatible rule systems out there and lot's to pillage so as to play the game at my table the way I want to play the game at the moment.
Too many OSR/ retro-clones....nay say I, bring them on I can always use a few new paragraphs of genius to "borrow" for my games.