I went from a 3.0 Z4 roadster to a 996 4S. The cars are 100% different. The Porsche is miles faster , handles better, is more stable, is more of en event , more satisfying to own in all aspects. The only downside to the Porsche is the cost of keeping it on the road. I spent more in the 1st year of Porsche ownership than I did in 5 years of Z4 ownership. Value for money, the Z4 wins hands down. If I was to sell the Porsche, I'd hunt down a Z4 coupe, no question. Would I trade a Z4 for a Boxster, no, but I'm happy I did for the 911.