My wife uses a slightly older version of the Tannus tyres on her commuter bike. She has been very happy with them indeed. They do ride like a firm pneumatic tyre, but she certainly hasn't experienced any issue with grip - even in this week's frosty conditions. Having said that a 'performance' cyclist might not like the feel or reported higher rolling resistance.
Fitting is a bit of a faff. Getting the correct tyre width for the rim is critical. Pins are fitted through the tyre carcass and these are snapped into place below the rim bead using a plastic tool. It can take quite a bit of force to achieve the 'snap', but once the tyre is fitted it feels like a very solid system. The manufacturer recommends the tyre is cut off to remove!