The feat should not be DM dependant. People should get cover against you a *lot* of the time. Fighting in combat? if there's a guy even partially in the way, they're getting 25-50% cover. Unless you regularly shoot at guys standing in the middle of a grassy plain with nothing around them, chances are they're going to get cover. If your DM isn't imposing cover rules or isn't making your enemies fight intelligently, then it's his fault this feat is useless.
Yes, Peerless Archer is better from what I hear. Of course, from what I hear, it's also way over the top. For those who don't allow that prestige class, or for those who simply don't want to take it for one reason or another, this is a good feat. Granted, I don't have access to the prestige class right now, but is there some reason the two couldn't stack?
Yes, if you go to epic levels, this feat will eventually become useless. In my mind, I think they should have required sharp shooting as a prerequisite for uncanny accuracy. But even so, many, perhaps even most, campaigns may never make it that high.
And yes, archers often have high attack bonuses, but when your opponent can get +10 AC by hunkering down behind a boulder, you need every attack bonus you can get. My 3/3 fighter/rogue elven archer was having a hellish time hitting guys in a breastplate with 9/10th cover.. you're talking 28 AC. Even with my very high +11 to hit, that meant 17+... that's not exactly what I would call an easy shot. The +2 made it 15+, which although not great, is still a 50% increase.
-The Souljourner