Yeah, Alpina is classic looking for sure.
XD = Chevy
Alpina = Buick
Mighty = Cadillac
XD600 is the triple model one notch down in the line up. I have one on my Clem Jr. Looks nice and no problems.
Supposedly the Alpina has 10sp compatible chainrings and the XD doesn't but that's just hearsay. One difference is that the XD has 4 spider arms and one hidden crank bolt. 110/74 BCD.