I enjoyed the first one - the destructive assets were nicely done, I thought. And aside from that it seemed a competent shooter at the least.Unless it's proven to be a lot better than the first 2 games, I wouldn't pay that much. I thought Red Faction 1&2 were fairly mediocre as far as first-person shooters go.
I played a bit of the second one but was put off by the fact that destructable sections of wall appeared to be clearly marked out for you, removing the incentive for exploration*.
Also, it seemed a little too gung-ho and brainless in comparison with the first.
(* At least that's how I remember it...am I right or am I thinking of something else?)