[QUOTE Am I missing something? And have disc brakes become a lot better than five, six years ago? Does it make sense to get the disc brake model of a given bike like the Sirrus or the Trek 7.x series or the Giant Eclipse for normal riding conditions?[/QUOTE]

Great question. We have two tandems. One has newer ultegra calliper brakes. These are absolutely great, and the rear one actually works better than the disk that came on the brake. My only reservation is that 700 *28 mm tires just fit. Our other bike has tpr spyre disk brakes. I don't think they actually stop us quicker, but they work with our 650b * 42 mm tires. Overall, if not for the tire clearance matter, I would stick with rim brakes.