Just discovered these recently.
I'm blown away by the quality, the ease of use, and the stability.
I've used a number of stands of all sorts, shapes and sizes, and quite a few when it comes to foldable ones. Many will be foldable and easy to carry, but not very solid or stable, many times you have to sacrifice safety for portability, but not with these.
Solid metal construction, nice weight to it but not too much, this thing won't bend, fold, move or shake, and it will safely hold your guitar or bass, no matter the weight. It is so annoying when a portable stand starts to bend under the guitar's weight. Also (very) annoying is when a stand is so low that you can't put the guitar on it with the jack plugged in... which is no problem with this K&M.
The rubber covering the base is also high quality, and this thing won't slip no matter what. This stand will fold to an almost flat profile of 3cm or so, so it won't take much space. Will it fit in your pocket or gig bag? no (unless you have reaaaally big pants ^^), but this stand remains very portable and is so good that it can also easily become a main stand and not just a portable gizmo. Really good price too. Already have 2.