It's a great jack, the bike is rock solid stable on it. The jack has a double locking mechanism so the bottle is never under pressure while your bike is up working on it. The bottle itself is an off the shelf unit with mounting holes in the base. If there was a problem with it I'm sure J&S would make it right.
Use mine after every ride. Store the bike on it. Seems more stable the higher you go, especially after you rest the jack on the locks. Only problem I had was the bottle jack, wasn't leaking, it was low on hydraulic fluid. Could not get the bike to the highest position, removed jack, added some hyd jack oil. Other than that, it's a quality well built tool. Easy to move around with the bike on it, got the extended handle and drain pan.