For the sake of engine longevity, I think the amount of boost is very conservative on factory offerings. My 1986 Porsche came from the factory with 215 hp at 0.8 bar positive pressure. Many of those engines have gone 250K miles. Mine has run 1.1 bars since 1998 with the addition of a special head gasket and a second oil cooler, the latter being needed only for track driving. The '87-'89 versions produce 247 hp with a larger turbo. If properly engineered and maintained, turbocharged cars last a long time. The downside is that they are more complex. I have seen 944 turbos financially consume people, literally eating them alive. Much of that is attributable to the owner's ignorance. That's how I got mine for a small amount of money in 1996. It was eating its owner.