Belt drive systems are far from high tech. They've been around about as long as the roller chain. They are used on motorcycles, but roller chains are still the more popular choice.

Pros are lover maintenance, belt drive systems on motorcycles don't need periodic lubrication, and they don't need tightening as frequently.

Cons: I think they are also less durable, and are of course impossible to repair. I believe they also have more friction than a properly lubricated and adjusted roller chain, but I might be wrong about that one.