I'll back up with JugglerDave says. When I had my Downtube IX FS at Mont Tremblant, a ski village in Quebec I climbed some pretty good hills with it. Some of them kicked my butt, but for sure you can climb. The stock bike is a bit of a better climber than mine, since I changed my gearing, but even at that, if you've got the legs, it's got the ability.
The only thing my DT does that I don't particularly like while climbing is have a little squeak in the handlebar quick release.