I went with the 34 (and a 26 for carry). It shoots like a dream for me. A buddy of mine who's a Glock fan, however, didn't like it at all. He complained that it was busting his middle knuckle and felt "snappier" than it should. He couldn't put his finger on exactly why, but it wasn't comfortable at all. He's got at least five Glocks and relies on them for self defense.
If I had to guess, it's because the momentum of the longer slide. That's just a guess. It works like a dream for me. If you like the Glocks, go for it. About the only two things you might want to consider (both of which can be changed cheaply) are the lighter "target" trigger that some (including Glock and Mas Ayoob) think is too light for a defensive gun. The other is the extended magazine release which may poke/gouge depending on your grip.