I'm having the same problem man. I have a level 18 Pidgeotto and a level 13 Hoothoot. I've almost always had a Pidgey on my team, but never really tried playing with Hoothoot. I like him so far and am still having trouble choosing. I might give Hoothoot a try just to do something new.
MKWii: BirdBird // 7500VR // * // 3309-3614-1729 A bong hit a day keeps the doctor away!
I think they're all the same to start with. But myself I would go with a Female Pidgey. That way I can train/evolve her into a very strong Pidgeot. Also becasue Pidgeot is my favorite Pokemon and females are generally bigger when it comes to this type of bird as most birds of prey have the females larger than the males. To me it seems like Pidgeot is stronger because of the 2 evolution levels. But it all goes down to whatever works for you the best as a trainer.
MY PSN ID: Sawblade5 Pokemon Diamond Name: Chris - My FC is 1633 1157 4209