Same. I was using some drivers that were regularly stripping screws. I ended up buying the Associated hex driver set (7 pieces) and haven't looked back. It's all about the tools.
I would say the problem is a combination of less-than-accurate cheap drivers, soft screws and simply using the wrong tool. I was using a 2mm driver on the smaller countersunk screws (like the ones used on mount the shock tower to the diff case). The associated set doesn't actually come with a 2mm driver, but a 5/64" driver. The difference? About .006 inches. Doesn't seem like a lot, but maybe just enough. The odd thing is that the Associated set also includes a 1.5mm for set screws and 2.5mm.