Just beaten this, thoughts below:
+Good graphics for a noughties game, although the blurry DoF effect gets annoying when aiming
+Western setting, good mix of towns, valleys, trenches, villages etc
+Duels add a nice touch although gets a bit repetitive
+Runs very well as you'd expect for an older game
-Less fun than Gunslinger
-Mediocre voice acting, especially Ray
-Aside from the sections where you can choose Wanted posters etc, it is very linear, compounded by the typical nonsense like having to clear pathways with dynamite and putting a crate of dynamite right there
-Some draw distance issues, especially with rocks and foliage whereby the LoD suddenly clips in as you approach, changing textures or making the shrubs change size etc
-Story didn't really grab me, most of the characters seem to make bizarre decisions with minimal explanation
-Lack of co-op seems strange given the game is basically based around progressing with a partner
-Poor enemy AI
Overall it was one of those games that you plug your way through because it is fairly simple and not outright terrible, but I wouldn't recommend it over the plethora of other shooters out there.