I've only ever shot DI-based AR-pattern rifles. Never had any issues with the gas system. Spending more on a piston-driven rifle because you don't want to clean it is pretty lazy to me, but that's just my opinion.
That aside, both of my ARs and my issued M4 never spontaneously combusted if I missed a cleaning. I think the issues with DI are way overblown. I'll try to find an article by a former SF soldier who ran something like 10,000 rounds through a DI rifle bone-dry and it worked fine.
TXARNG: 2007 - Present
"We're gonna turn left!!" - NASCAR, in a nutshell.