I just went through this dilemna about 2 weeks ago. Dealer had an '07 FX45 on the lot and '07 FX35. Both were identical; tech package and were black. The only real difference was that the 45 had the expresso interior and the 35 was black. After driving both, I ended up getting the 35. It was $4k cheaper and had half the miles (12.5K vs. 25K). I thought the 45 was smoother obviously, but it didn't feel significantly faster. I also like to tinker with my cars and the 35 has much more choice in that regard. The main, sticking point was that the 45 had the expresso interior though and my wife thought that was an abomination. Haha.