When I started running a D&D3.0 campaign I had to give up running GURPS, because I couldn't get anyone to play it. Even though I find it to be a better game system for my gaming style, most of the people wanted a system they had at least a passing familiarity with. So, I changed systems, but not by my choice. If I could get them to switch to GURPS, I would gladly give up D&D and never look back.