If the saddle on the DB is set for your riding position, I'd say the frame is a great fit for your use, but only you know if it fits comfortably. The DB is a much better quality bike, and is set up very nicely for commuting (great job!)
As 65er mentioned, you can get a larger "big" ring on the crank for better cruising gears.

Either bike should get you up your few "wicked" hills just fine.