I've actually gone through a couple pairs of these. Of course they don't get the best mileage out there for me as I traverse a bunch of asphalt and cement before I get to play in the dirt.
I've tried several different options, most of which were knobbier and these are all around better in my experience. Road noise was decreased, stability at high speeds was increased, wear was better, and most important...grip in dirt awesome!
As an all around tire like I need, this has become my new standard. However, I do swap to street tires for my non-dirt touring trips because these do wear faster on the roads. If you are looking for a tire that works great everywhere and are planning to do a decent amount of dirt, this is the tire for you. If you "might" hit the dirt, but normally don't...this tire may not have the same positive impact.
As with knobby tires all around, there is a decrease in street response, increase in distance when braking, and such.
I can balance the bike very well on these tires, make tight turns, and take corners at speeds (unlike knobbier tires), but it does take some time to get the feel and build the trust as they do feel more like traditional knobs.
If you are going to have a mixed ride (street/dirt), give these a shot...they may become your new regular Enduro tire.