I went back and forth from AW to SSII over the course of about 3 weeks. I was about to switch to SSII when I found out it was too late to switch. I am now waiting for my AW M3 coupe, estimated arrival in early May. No worries, I am sure I will love it since I have yet to see one on the road yet.
My advice.. Call your local dealers and see if they have an M5 in Silverstone. If so... definitely drive there and check it out even if it is out of your way. Silverstone is absolutely beautiful IMO, it definitely has an iridescent character where the color looks slightly different from day to day. Make sure you see it in person before committing to it.