I have 26 x 1.5 Nimbus Armadillo on my Specialized Hardrock MTB. It rolls fairly well on the pavement. Good enough for commuting. I even take it on some dirt trail where thorns are present and yet have a flat. On gravel trail, they do slip on the turns. Yeah, like other said, they do ride on the hard side. I set the front shock to the softest setting and used a cushy saddle with spring. I've never tried SMP and cannot comment on them.

Be warn, the Nimbus Armadillo is a PITA to install on some rims. I had to use a Quik Stix to get them on.