AR rifles are fantastic, but overated. Much like a .45acp pistol I wont mention. I read something about Soviet armored troops sleeping in thier vehicles for fear of Afghan Muj shooting at them with Enfield .303s . What im getting at is that the best rifle is the one your comfortable with and shoot well with.
Overrated? I'd say the AR is underrated if anything. You can read all sorts of crap about the 5.56x45 being an underpowered cartridge unsuitable for killing small vermin. I've read guys claim that a 5.56x45 would not penetrate a standard car windshield. It's difficult to compare a bolt-action rifle that has an internal 5 round magazine to an AR. That's not to say that the Enfield can't serve a purpose, or would not be deadly in the hands of the right shooter, but the two rifles serve a different purpose in a modern combat scenario.
Back on subject, Why wouldn't you want an AR? Unless you're partial to another comparable semi-auto with detachable mags.