actually...honestly...seriously.... I have launched the game and that was all. :?
Intro video started in 5292x1050 (stretched), menu in 5292x1050. All I had to do is to hope the game would look correctly and it does. (just like RF:G)
The HUD is absolutely no problem to me. I would be nice to have it centered and not so stretched but it's NO killer at all. In RF:G it clearly is.
So sorry for now, I have NO IDEA where the settings are saved, I searched for them.
Make sure you run the game with desktop set to eyefinity res. I can't think of anything else to suggest. Newest drivers of course. -.-
All I can say is that I don't want to miss out eyefinity in this game. It's a whole lot better experience - imo it's meant to be played like that. Stupid developers STILL aren't getting over it.
Game options actually say 640x480.
If your game launches in eyefinity resolution I would recommend to NOT CHANGE ANY graphic settings.
Otherwise you may overwrite the resolution and will never get it back again.
I'm stuck at MSAA 2x only, but it's ok. If I set it to anything higher the game may accept 640x480. That would be a fun-killer.