I've got one and it works great! I use the suction mount on my 2008 race bike, right on the speedo and it sticks wonderfully. On the tail I just use one of the included sticky mounts. I've been in two minor crashes and they've held tight.
Link to original page on YouTube.
Link to original page on YouTube.
I've had that "jello" effect but that was only when mounted to the side of the fairing on my classic race bike. And I prefer to use the open backed case on the 250. I rarely see speeds near 100mph (and that's on the track) and the open case picks up the engine/exhaust sounds so much better.