Stardock is giving away free UI support: http://www.youtube.com/watch?v=NXK7BtheeUA (only 'catch': your game has to be available non-exclusively on Impulse too, otherwise it's free ) More info here: http://forums.elementalgame.com/378131
I think the difference is that you can easily skin the Impulse stuff. They made an overlay like that to launch Total Annihilation. It's really easy to change stuff, like lets say the rather ugly Atari logo... That was one png I just switched. Did wonders for the design imo... I'm not sure if you can change the looks of the Steam interface much but Froggy said you can basically rework the Impulse overlay to perfectly blend with your game. IIRC the Steam interface in SupCom2 looks exactly like Steam. I don't know if that was on purpose or if GPG can't change the design.
