I can recommend Zero-K (http://zero-k.info/ http://zero-k.info/) and NOTA (http://nota.machys.net/ http://nota.machys.net/) as very polished AAA RTS games based

I can recommend Zero-K (http://zero-k.info/ http://zero-k.info/) and NOTA (http://nota.machys.net/ http://nota.machys.net/) as very polished AAA RTS games based on SpringRTS. As is always the case for games the available screenshots/media don't reflect the actual gameplay. I suggest you give it a try :)