Saw my first ones yesterday. Rather unusual look. Sounded a bit different also - bit more of a whirrrrrr. Read about them a bit back. Cost is about $1,200 per tire and rim, but they do replace two separate tires. If recapped at the right time, each one is suspose to run something like 800K miles. Problem is a flat on one on a loaded cab or trailer puts them to the side of the road waiting for service to show up. Unloaded, they can probably make it to a repair shop, but likely have to wait for a replacement to be shipped in. Payoff is suspose to be in weight savings - more cargo weight. From what I read, mostly used by local delivery services who can keep ready spares and on-the-road service at hand. Anyone have more information on these. Just curious.