Yes. It does the job superbly. Dry shorts even in heavy rain.
It took me a while to fit it and even now its not a neat as the promotional video. It does stay in place and does the job but it does 'unclick' from the seat rails if you touch the Ass Saver in moving the bike.
I think my issue maybe that my seatpost is quite 'tall' and fills the underside of the seat which makes threading the Ass Saver through a bit difficult AND I have my seat all the way back on the seat rails too. I'm using an Easton carbon seatpost and Fizik Gobi saddle
I can see on my other bikes with Thomson seatpost and Fizik saddle it'll be easier.
Would I buy again? Yes, absolutely, but might go with the regular Ass Saver next time (not MTB) just to see how effective the smaller version is