Group Policies...
...rock my world. As you mentioned, with GPMC and the new preferences and XML based files it's actually a very good systems management and configuration tool for small and medium enterprises.
Rightly point out that for complex enviro's and large companies it's a bit messy keeping track (although I think GPMC and MDOP have helped with that a great amount).
One point though - if your using Group Policy and want change control and the other nice bits MDOP provides then your probably going to be a Volume Licence customer. 5 OS licences is still the criteria for an Open contract - I just can't see why a shop with less than 5 machines would be worried about change control!!