Hi Tomo67,
I've owned a Uli inflatable for about three years but only used it on holidays up North in the winter time. It's been an amazing bit of gear for the family to try and trash and have a bit of fun on and it has worked OK for a bit of fitness paddling.
As for glide, it has very little, and although the board is fairly stiff, it still bows with body weight on it and has pretty poor glide, especially compared with a quality allrounder or race board.
The inflatables have their strengths, but glide isn't one of them, neither is surfing. However, they are nearly indestructible, roll up small and serve most family needs quite well. We've gotten massive value out of ours and will keep it for the family holiday as well as taking away wave and race boards

Take a look at the Hobie Inflatables here
http://www.hobiesup.com.au/about/atrs/inflatable-10-8/DM