I drove a 2010 M6 with the SMG on Monday. It was somewhat quicker shifting than the 2007 M6 but there was still a noticeable lag even when shifting at high rpms with the mapping as aggressive as possible. I also drove a new 2009 M3 with the M-DCT. Lightning fast shifts and excellent performance in all modes - very much like the Porsche PDK. I would buy an M6 with the M-DCT transmission if available but it is not. The dealer indicated maybe the M-DCT would be available in the 2011 model. So, I am ordering a new 2010 M3 with the M-DCT. Not having that third pedal in a performance car will be new for me but I am sure I will get used to it and appreciate the flexibility and convenience in what will be my daily driver.

Thanks for all the comments. The varied personal preferences is why we have choices. I respect everyone's perspective.

 

I don't know but I'll probably get flamed for this but to me comparing SMG to DCT or PDK isn't quite fair. SMG uses a single clutch and hydrolics to change gears where DCT and PDK both are two clutch applications.DCT and PDK are the future and are fast and so far more "reliable" by reducing clutch wear and SMG has been around since the e36 M3 (in europe I believe as SMG I) Everyone is conpairing a 15 year old technology to a new one technically. My friend has a e60 M5 with SMG and those bangs in S6 are phenominal... That's why I'm gonna get a SMG e46 M3 over a 6spd.

But believe me, if I was getting a e9x M3 or a new carrera... DCT or PDK (respectivly) all the way!

 

Of course you are correct regarding fairness of different generations of technology comparisons. However my original point of this thread was determining if the shift lag in SMG transmissions was common or an isolated incident with the 2007 M6 I drove. We have all benefitted from technological advances and I want my driving experience in a performance car to equal my expectations, which are admittedly high. Personally, and it is only my opinion and preference, I find the M-DCT to shift like a true paddle shift F-1 type transmission where I did not get that same experience with the SMG.

I do appreciate the responses I got to my original post and find the experiences of others to be helpful. Once I get my new car I will be weighing in on mods in this forum. I found the experiences of others infinitely helpful in making some mods to my 08 911 Turbo. Thanks to all for you comments!

 

If you compare the two, the M5/M6 will have more kick and power at the high range. I heard the M5/M6 really pulls away at the higher gears (that V10 is crazy strong). I would love to be feel that kick in the M5/M6 in S6 one day.

 

That "kick" in S6 will cause my sunroof shade thing to slide back a few inches when it shifts.