[Perfectlap]

no matter how much power you get into you'll get "used to it". Kind of dangerous condition. That's what I loved about my puny 1.8 Miata. It was a tuna can and when you were doing 70 you felt your speed, you respected it.
The 911 has more than enough power for high performance driving as does any Boxster. I think you have to evaluate what factors other than power will make you happy. The I prefer the styling of the (2002-2004) 911 to the Boxsters and that's a big motivation for many. Scratch that itch if you feel it because well maintained Boxsters will always be available for even better prices.