I bought a manual 5 speed in 1999. I was perfectly content with its punchy low-end torque. Had never driven an auto tranny 4 speed until today, when the dealer loaned me a new one while my car was being looked at. I logged 70 miles in Tucson traffic. The diesel engine and the auto tranny seem made for each other. Light changes to green, we're all lined up in three lanes, drag race style, and you're the first kid out of the blocks without much effort. It's not quite as fast on acceleration as the manual, but it's a hell of a lot easier to drive in urban traffic. If my driving environment was 50% urban I'd have an auto tranny. But it's not, so I'll hang onto my M5.
As for mileage, it's almost a wash. 49 highway vs. 45 highway, 41 city vs. 35 city.
The M5 has the higher numbers.
[ June 14, 2001: Message edited by: blugg ]