Although mechanical disks are best, IMHO, V brakes, as found on the TREK 520, are perfectly adequate for most touring situations (where there isn't any mud clogging the brakes and rims). The only brakes out there that are sometimes not suitable for touring are the caliper brakes found on road bikes. This is because there isn't adequate braking power while going down steep descents when loaded.
However, the wheels that you get with the 520 are not so great. I watched several 520's fall apart on the Southern Tier last year. Also, I greatly prefer STI shifters to bar-end shifters.
Although the Utopia has mechanical disks, the rest of the componentry, including the wheels, is marginal. The straight bars offer limited hand positions, an issue which can be only somewhat addressed with bar ends. In addition, the bike's frame geometry is more like a mountain bike, which after many hours in the saddle will not be as comfortable as a touring bike. Also you will not be as aerodynamic.
You should definitely test ride any bike for several hours before buying. My prediction is that you'll want to get off the "Utopia" as soon as possible.
Before you make a final decision, also check out the Cannondale T2000 (msrp $1600). It has a more suitable mix of components for touring. A fallback would be the Cannondate T800 (msrp $1300).
http://www.cannondale.com/bikes/06/CUSA/model-6TR2.htmlIf you add up the weight and cost of racks and panniers and keep in mind that 2/3's of breakdowns while touring are attributable to racks, panniers, and rear wheels, you will conclude that a BOB trailer is lighter, cheaper, and less of a problem for rear wheels than traditional panniers. Also, the BOB bag is waterproof.
There is plenty written elsewhere about trailers versus panniers.
Good luck.