The respawn time is the only thing I don't like. I'm sure it's a server side option that can be set so I'm not worried.
One thing that I don't like, but is a minor issue, is the lack of use of objects. I love how in CS:S and DOD:S, all the objects on the map are not static - if you shoot an oil barrel it moves. However, in the beta, there is none of this. On one hand it gives me cover so that's good, but I'd like to see better use of the source gravity engine.
Also, the train on Well is fracking HILARIOUS! I laughed my butt off when I got caught on the tracks by accident.