[ibimmer954]

Background: I own a 535i 6MT now. I used to own a 335i E93 6AT Steptronic. I have driven the 135i with the 7DCT on a test drive. I do not have a whole lot of time in a F10 8AT.

I'm going to assume the 8AT in the 535i/550i is very close to the 6AT that's in the 335i E93. They are the same manufacturer (ZF). The 8AT is one generation newer. But they are both based on torque converters instead of the clutches present in the 7DCT.

Starting from a stop, I feel the 7DCT has more lag than the ZF autos. The tranny has to "bring up the clutch" to get going. You don't get that effect on TC trannys. Punching the gas in a 335i 6AT in Sport Mode, you have the feel that you're going to go "right now". The 135i 7DCT had a little more of a "wait for it.... GO" type feel.

But once you are going, the 7DCT shifts between gears are incredible. The downshifts are practically instant. Way faster than you could do on a 6MT or 8AT. It's almost spooky how fast it shifts. When using the paddles, the 7DCT shifts were equally fast. No lag, it just shifts right now.

To be fair, if you have a 6MT it takes a little while to get going as well. The 7DCT can start off a little faster than a human. But it won't feather the clutch to get a power take off like you can in a 6MT.

The good news is that 6AT in my 335i kept the torque converter locked almost all of the time. You could do engine braking in that car. If you let off the gas and punched it again you wouldn't have to wait for the TC to get a clue. It's already locked. The only time the TC unlocks is when it is shifting. It's not a very squishy feel.

I'm happy with the 6MT in my 535i. It's a very smooth shifter and feels great. But you can't get a 6MT with XDrive in the U.S. The strategy from BMW seems to be that 6MT is for "performance" drivers. And performance means non-Xdrive to them.

The only place you are going to see a DCT tranny on an F10 is in the M5 anyway. I'd be willing to bet you won't see a DCT in an F10 any other way for the next couple of years. No M5, no DCT.

Up until a year ago when the 335is was introduced you could only get a DCT in the 3 series on an M3. And we're at the very end of the E9x model lifetime.

Edit: Wait a second, your car list says you own an X5. That must surely have the ZF 6AT in it. The 8AT in the F10 is going to be very similar to that one, except that it has more gears.