I have a Trek 7.2, and it's a perfectly good bike -- I ride it to work in NYC most days, and it has held up through a lot of abuse. I've also taken it for some 50 mile rides -- it's not perfect for that, as your hands get numb after awhile, but it's certainly possible. I have the non-disk version, because I don't understand the need for the disk brakes in city riding -- I've never had any trouble stopping in any conditions. (And there's a lot of quick stopping in NYC traffic.) I tried out the Specialized as well, and liked it -- I ended up with the Trek just because I liked the color and size they had in stock.
That all being said, it's not so much a "flat bar road bike" as it is a "hybrid." If you're looking to commute, it can be a good option -- but it's not going to be as fast as a road bike. It's a commuter bike, first and foremost, and it does a great job at that task -- but that's all it is in my view.
By the way, we also have a hybrid forum -- if you haven't already posted this over there, it might be worthwhile. Those guys may know a bit more about the particular types out there.