I would agree. I do not like a lot of swapping. Not to speak for Trips but I think he is doing the same thing I did. Remove the 20" summer tire that came on the OEM 20" rim and put on a winter tire. Then use this setup for winter only. I don't think Trips and I know I am not, going to be swapping back and forth. I run a 21" for the summer. I do they same for my M3. I have a 19" street summer, 18" winter and a 18" track tire/wheel combo.

The trick is what to do with the brand new 20" stock summer tires you take off. Either sell them or I would like to put them on something for a track day.

Trips, Not sure I would worry too much about the larger size rear. Unless you are driving in snow all the time. I live in WI and while it is cold I am only driving in deep slow a couple of times a winter. If you lived in the UP Michigan it could be a problem.

I did have to drive the X5M home from Chicago in the snow on the summer tires. I have driven worse.