I bought one of these to put my 1200GS on. Putting the GS on this thing is really a challenge and I'm a pretty big guy.
But once it's on its really a pleasure and easy to move the bike around. I bought a second one with the purchase of my K1200RS. They operate just like the You Tube video.
You do need to have a smooth garage floor. Stone or large cracks are going to be a problem.
Wunderlich (sp) also makes one that I think is a little beefier than the the Park n Move. I one of each and I do like the Wunderlich model a little better - the wheels are more robust.
I couldn't imagine living without these little devices again.