I purchased this synth stand to complement the K&M 18941 two-tier extension after my older brand-less stand finally broke following extensive touring.
Initially, I was reluctant to purchase a stand for the combined price of the 18990 stand and 18941 extension; however, once I unpacked it I'm glad I did.
Pros:
My first impression of the stand was it's solid quality, and I'd say it will take a fair amount of bashing whilst loading and unloading, and the rubber caps are taut so there's no fear of losing them in the process. It's easy to fine-tune the height with the joint's five-degree intervals.
The K&M 18941 synth extension fits perfectly on the ends and they're also very easy to remove which makes it easy to throw them in a bag to alleviate the weight of carrying the main stand.
Where I'm only using a DSI Mopho X4 and a microKorg, I have no doubt that it'll hold heavier synths with ease.
Cons:
None!
Overall, great quality and where I'd definitely buy again, I probably won't need to for a very long time!