Take them out for a test ride if you can. The Tiburon has front shocks while the KHS doesn't. I've never ridden the Urban-xpress but it looks like it's designed for a more aggressive riding position than the Tiburon. The Tiburon is set up as a pretty relaxed ride. Also depends on what you want to hook up on the bike, rack, fenders, nothing...
I've got a Tiburon set up as my commuter.
I think it boils down to whichever bike you like better. Personally I'd lean toward the Urban-xpress style rather than the Tiburon w/the front shocks and more upright position. Then again, my commuter is a more upright ride w/front shocks, and I just know that I prefer a more aggressive riding position & regular fork...