I've been eyeing these stands for years and was finally able to invest in them. I have to say the wait has been worth it.
I'm using the stands for a standard two speaker setup. Overall the build quality is classic K&M; sturdy, stable, heavy-duty, and solid. The round floor plate is WAY bigger than what I imagined, even when I knew beforehand that it was 45cm in diameter. It takes up quite a bit of real estate, but as a result you'd have to do some pretty serious tackling to get this to fall over.
The top plate is stable and level. Just make sure your speakers work well with the measurements and you are good to go. It doesn't have (nor does it come with) any rubber/other stoppers so you have to figure something out for that yourself.
The stand is aesthetically minimal and utilitarian, just the way I like it. Black, matte, functional looking, and doesn't disturb the eye.
The price tag is a bit hefty, but it really is justified by the quality. You are paying for something that will serve you for the rest of your life. I can't imagine this breaking or otherwise failing to serve its purpose. Bite the bullet and secure a solid future for your speakers.