I have the Primo Comet kevlars on my trike and like them just fine but the next set will be a Schwalbe Marathon of some sort (probably the Racers). Only problem I've had with the Comets is that they are not very cut-resistent. I've had glass trapped between the casing and the rubber which eventually wore through the kevlar and into the tube. I also have some nasty cuts on the rear tire that makes me nervous. Comets are thin and fast and a great value but for touring I'd be a little leary of them.
Blackwall with the reflective stripes rule!