[-Josh-]

Generally speaking on any car with FI, you're going to start getting the most wear on the piston rings, especially an engine that wasn't originally built for FI, that doesn't necessarily mean that those engines cant handle it, it just means they weren't built for it, and will show wear much quicker than a OEM turbo engine. Saying that a turbo causes more wear than a supercharger is like saying a V8 wears more than a 4 banger.

Also i think what Jayson meant about turbo's abusing oil is that, when you add a component such as a turbo that requires engine oil for lubrication, it's just one more thing the oil has to pass through and can lose viscosity much quicker. MOST belt driven superchargers however use their own lubricant and don't need it changed that often. There are some centrifigal superchargers that get tapped into the oil pan on installs and use engine oil but those are usually aftermarket superchargers, not OEM.

Also when you add forced induction you may find that your valv train components will see a little more wear than usual as you usually have to play with timing a bit.

As far as carbon on the exhaust valves, just run a fuel system service/cleaner through the system, that should clear them up pretty good every once in a while.

The reason I would prefer turbo's is simply efficiency, it's been proven time and again a good turbo will provide better gains than most good supers. Hot Rod Magazine has already said that turbo's are quickly becoming the prefered type of FI in racing today, among all car brands.