well since we're reviving a three year old thread I'll give my take on the Armadillo Nimbus 1.5's after three years of use. I'm still using them. I'm getting about 5k out of them with minimal flats. What I mean by that is I'm getting perhaps one to two flats out of each tire. Excellent puncture resistance. I ride every day to work year-round. And I've ridden thru all kind of road debris. My last flat, I ran over a belt buckle that had been flattened out by car traffic and somehow ended up in my tire. But riding thru glass or other stuff just does not bother these tires. I was having a problem with one set where the rubber outer casing was coming apart and swore I'd switch to Marathons to see how they match up. But I haven't yet. Since, they have changed the design on the latest model that I've bought and they look to be just as durable.
The ride quality? I'm not the type of person to notice too many idiosyncrasies of riding on a bike tire. People say they ride too slow, or too heavy. They don't feel any different than any other tire I've ridden on other than the fact they last a long time and seem to be bombproof to anything I encounter on the road.