Been riding a Tricross (comp) as my road bike for the past four years or so -- averaging about 3,200 miles a year. I wouldn't give it up for anything. Much of my riding is my commute, which can be flat and fast or hilly depending on route. My usual route is 28 miles round trip.
Just got back from a morning ride with my wife, and we decided on a whim to cruise down a few miles on the top of a grass covered flood control levee with some single-track type paths...no issues even over the rocky parts (she's on a cross bike too).
I usually have 28mm gatorskins on it, but in the fall when I'm commuting in the dark and there is more debris on the road I'll put on 32mm tires with more tread - the extra cushion is nice, and they arent' much slower.
This past weekend we both competed in a fairly large sprint triathlon. I took the fenders, locks, lights, etc off -- and I out climbed and out road large numbers of "road" bikes and even some of the pure triathlon bikes...even those being ridden by people half my age. Maybe I'd have been a couple minutes faster on a road bike, who knows.
IMO cross bikes are a great all around choice for road riding, unless you plan on fast group rides -- and even then it motor matters more than the bike.
As for the brakes - I have the original Avid Shorty 4 that the bike came with - put on some good brake pads (I like the Kool stop dual compound mountain pads) and toed them in a bit - not shudder and plenty of stopping power. And I live on top of a bit hill so I need to be confident in my brakes.