For the 6M, I have 500 miles on the car, FWIW:
As everyone else said, 3rd Gear, Sweet, even with 5500 Handcuffs.
The Feel of the shifter is precise and very snickety (Good Thing)
The Engine seems to be made for this transmission.
Having True Control is priceless.
Shifting could be shorter
1st Gear is LOW, LOW, LOW
6th Gear is not much of an overdrive 3100 rpm's around 80mph
Clutch is a little light and engages later than expected
Most of my cons come from not being used to the vehicle. My latest standard tranny is in a 08 Jeep Wrangler X, so when I drive the M, from that, the M feels FABULOUS. Yesterday, I was cruising the backroads and it really started coming together for me. The design of this car, the precision, the way everything works in unison. Power Button, AWESOME. The more I drive it, the better it is and better I feel about my decision to go with the 6MT.
Took a ride in a DSG car and was very impressed with how smooth and how fast it shifted. Much better than the last SMG car I test drove. I hated SMG.
2008 M3 Jerez Black "Fast"
2006 BMWK1200S "Really Fast"
2006 550i, "Hers"
2008 Jeep Wrangler X "For Dirt"