After reading countless reviews where this stand was recommended for heavy pianos (like my mp11se), I decided to order it and give it a try. Unfortunately, when I play particularly loud and fast pieces of music (e.g. Rachmaninoff), the piano and stand get quite the front-back wobble/vibration going, to the point where it is distracting and disappointing. It is not enough to really create an error as my fingers still come down where they were supposed to. However, it removes the illusion that one is playing an acoustic piano.
Thomann pointed out that this is not uncommon with heavy pianos with this style of stand, so return shipping would have been on me. Thus, I decided to troubleshoot different ideas to get the wobble to go away.
Putting it on a rug helped. The final change was a tension rod placed between the base of the piano and the top of the horizontal part of the leg, one per side. That has removed essentially all wobble.
It is confusing how so SO many people (many with the exact same setup) say this stand is 'rock solid', but mine is not. I think it comes down to how you play. Fast and hard - maybe try the K&M 18950?
