I mentioned before that I now have ACAD2010 and just downloaded RST2010. Regarding RST, I hope you like the ribbon interface in AutoCAD or MS Word for that is your only choice in RST. Now is that a bad thing? I personally don't think so but it will take time to get used to it for sure.
But what about AutoCAD? You do have the option of menu bar/toolbars as in the past. But should you? I don't think so. If you have MS Word and other applications along with RST all with a ribbon, why would you use AutoCAD with one?
Personally I feel strongly enough that even for the corporate AutoCAD menu WPM uses for the Structural Services group (my area) that I have removed the menu bar and toolbar elements so that the menu is only a ribbon format. The logic is that it will aid in people getting used to the ribbon for RST if that is all they ever see and they can't fall back to the menu bar format. Now I just have to wait to see if the logic pans out.