I have been looking to come to the dark side with a 5 series. I drove the 650i at Hellinger Toyota it has some RPI mods ( intake/exhaust) it was nice but lacking some features. The other two I drove were an 06 and 08 M5 all I can say about that is I NEED one. I was oing to get one at the end of the month but I think I am going to wait until spring. I can't say there was anything about the M5 I didn't like. Made my G seem like a POS