Jumping off speed bumps, snappy handling, smoothing out the potholes and cobbles, biiiiiiiiiiiiig skids (though to be fair the Kaff pulls them as well) - all great.
But... I always forget how much harder work it is than by road bike. I wasn't actually much slower, but the effort was much bigger. I can understand why, when MTBs make up such a large portion of the new bike sales market, people get turned off cycling. If you're not fit then it's such hard work. I remember Mel having a moment of epiphany when I put big slicks onto her MTB and the first ride after that...
(last night discovered a crack in my fixed wheel tyre (Halo Twin Rail Couriers are lovely tyres, but fragile - I'll be changing brand) and rather than put a spare Vittoria Rubino on, changing the pedals over onto the recently serviced MTB seemed much more sensible...)