I've owned an ASR-X since around 2000. The knobs failed in probably 2001. By failing, basically you will spend 10-15 seconds minimum every time you need to change a preset (more when scrolling through larger directories, like drum sounds; in fact I often just give up first).

The numbers go up when you want them to go down, etc. VERY frustrating, and from my readings online this is a common, maybe universal thing with these machines.

Other than that, the thing is fun but with this critical failing it is unuseable for the most part (though I still use mine here and there but then I'm just too lazy/cheap to buy something else.)