Personally I've always played the 120 man units from day one - so I've probably become accustomed to them. Admittedly I'm one of those people that fires a game up for the first time and goes straight to the options/settings.

Windows 7 may bring new problems and may not. There have been issues with the resolution being locked at 800*600 for some people, though I think that's only been reported in MTW so far.