I played through RF about a year ago. You can edit the .ini file to get higher resolution, so I was able to play in 1600x1200. I'm not aware of any gfx mods, as it's not really a popular enough game to warrant any major projects.
The storyline was pretty unmemorable and the textures very bland - still playable though and it had a decent range of weapons. I'd rate it above Red Faction 2, but not as good as Chaser or C&C Renegade which both have a similar feel to it.