This ball is easy to inflate, the measure that came with it made sizing easy, othervwise its hard to know just how far to inflate. The surface of the ball is easy to grip, no sliding hands like the other 'smoother surface' ball I used to own, I am 5ft 4 and the 55cm is perfect, my previous ball was 65cm and way too big. You also get 2 bungs which s handy in case you lose one, plus a neat little tool for removing the bung in case you need to re-inflate (or deflate) I think most gym balls do go down a little in time, so thats not abnormal but at least you dont have to break a nail or risk puncture by trying to get the bung out.