The K&M 26740 is a very solid stand! I am using it with the Yamaha HS7 powered monitor speaker, and the mounting-plate of this stand is the perfect size for the speaker.
I have been very impressed with the weight of the circular base piece, which means the stand cannot be easily tipped if you bump it. My speakers are merely resting on top (not stuck down) and even if I give the stand a decent whack the speakers don't budge. It even stood up through an earthquake!
The vertical pole is nice and thick, and the height-adjustment is rock solid once set. It includes both a slot which accepts a crossbar to ensure the height adjustment cannot fail and drop the speaker, and then a tightening mechanism which makes everything solid and prevents wobbling.
It is a pricey stand, but in my experience the less expensive ones aren't usually worth bothering with; they are often flimsy and cheaply-made, and can tip over easily. For my money, this K&M is the best monitor stand you can possibly get.
Well engineered, highly recommended.