YECH! I hate top tube cable routing. To me it's the hallmark of a cheaply designed bike. I figure I stand over the top tube at least 1000 times for every one time I carry my bike on my shoulder. I'm forever moving the little cable donuts around with my junk, and now I've got small surfaces scratches from cable rub. I've never once carried my commuter on my shoulder, and I don't really do that with my mtb either. Maybe if you're racing cx or mtb. You won't be with this bike.

Personally, I'd get 3 hydraulic guides brazed onto the underside of the top tube and run uninterrupted cable housing from lever to caliper for the rear disc brake. That's the way you must do it if you run hydraulic disc brakes anyway. Might as well leave the option open. This way, you can also lift the bike without moving the cable around. These braze ons are going to be standard on your seatstay for disc brakes. Internal cable routing is nice, but forget hydraulic brakes.

These are the stick-on guides for reference, but braze-on ones are avail too:

http://aebike.com/page.cfm?PageID=30...ils&sku=BR7847

The front der and rear der cables I'd run with standard cable stops on the downtube.