I agree, as much as I respect DRob, Jimmy Smith runs some of the prettiest routes you'll see and when DRob gets beat in coverage for a big play it's usually due to him getting his feet tied up on a double move or similar circumstances. That said, Aaron Glenn is a vet who can handle some of those nifty moves from Smith, and he stands a good chance of containing Smith as long as he has help over the top.
Between AJ and Smith at this point in their careers, AJ would obviously be the guy you'd choose if you're developing a franchise, but it'd be damn near a toss up if you just wanted a WR who'd help you win now. AJ's definitely got Smith in nearly every athletic category at this point, but Smith has proven again and again that the trick's he's learned come in very useful. They're both playmakers and when given the opportunity I've seen them both make some jaw dropping catches this season.