I've used them. I borrowed a pair at the track. You still need another stand to get the bike up on them. You can adjust them to put under your frame sliders or your solid mount foot pegs. Then you have totally unobstructed access to the front end or to the swingarm. There are other ways to get these things done with those stands, but they were handy.
Yep in order to use these you put your bike up on stands then move the jacks in. I like the idea of these stands. They make taking the front end apart easy, with no other stands can you take the tripples off to change the head bearings, but with these you can, and the way i look at it is, you only need 1 set of stands.
If your chaing the head bearings use your rear stand and 1 set of those stands. And if your installing your shock, put it on the jacks, and your front stand.
Neet, personally if you work on your bike a lot they are nice, or maybe split the cash between a friend and share to save on the cash.