Never heard of Red Fraction. Sounds likesome sort of hardcore maths game? Haha. Short answer, NONE of them. With Dungeon Seige, Child of Eden and F.E.A.R 3 just round the corner, Save yor money! You can pretty much by-pass both game with the knowledge
that you havnt missed a great deal.
Its difficult to say which is better, while im enjoying both, neither are outstanding and are average at best. The destruction on Red Faction is great fun, but the story and missions let it down, only done an hour or so and all ready 24% of the way through
Duke is fun also but long, long loading times and frame rate issues are ruining it for me. Give them a rent and buy some points for Trenched at the end of the month.