I'm not sure of your reasoning for not wanting a traditional road bike, so it is hard to reply with any certainty, but you might want to consider a CrossBike.... Looks more like a road bike, but is suitable for gravel roads, and maybe some light trails.
The trek 6500 should be good for long distance rides. The only problem with riding it (or any MTB) on the road is that the gears are not set up for it, and you'll run out of gear really fast. MTB usually has a 44t or 46t big ring, where-as a road bike or cross bike will have a 53t big gear. I've ridden road on an MTB, and you'll probably spend 80% of your time topped out in one of the biggest gears....
If you'd give us a little more on your reasoning, and perhaps more about the intended use, people may be able to add a lot more.
I also like the Giant XTC. I have one and I'm very happy with it. I use it on my longer rides, but I have a road bike for the road....