Oh, I'm guessing this was my mistake:
http://forum.ppcgeeks.com/showthread.php?t=79579
I thought that was a WP rom. And I was just comparing WM6.5 and Windows Phone with Vista and Windows 7.
I was thinking of going back to MR's 6.1, I'll take a look back into the best roms thread.
My next, and I think the more important question for me, is do I need to downgrade anything to get the earlier roms to run? I didn't think I needed to, but it's been a long time and I'm a simpleton