Im using the 2.3's and I love them. They break in very fast and have concealed laces so there is nothing that can pinch your toes that many people complain of. The material is this flexible "leathery" stuff that molds to your foot. I have narrow feet that are relatively flat and these shoes work great for me. Also love how the tread on the bottom of the shoe is setup.
Good durability (with 6 month guarantee) and they are on sale right now . . . Great shoe. Only negatives are breathability and weight. Not a heavy shoe but not a light one.
I also liked the asics gel res II's. They took longer to break in and pinched my toe a little bit. They were very light and comfortable after the breakin. These shoes are not for people who burn through shoes though. Low durability for a 100 dollar shoe.