For $300 put the Dinan tranny software on. It totally eliminates the 2-1 shift issue. I had the latest software from BMW on my 2003 4.6is prior and it still had the problem. Now that I have the Dinan version it's perfectly smooth. Also, sport mode is a beast!

I'm not a big Dinan guy, think most of their stuff is overpriced for what you get. But this is very much worth it. Probably will save my tranny and TC, at least for a while.