first off was impressed that assembly was pretty quick and easy - the fiddly bits are pre-assembled, you just basically have to join the sides together with linking tubes, adjust your shelf heights/angles for your keyboards (that part is a bit more fiddly) - then you're good to go. I've got a couple of heavy analogue synths on the first two tiers, seems solid, and don't expect any issues when I add another synth on top tier.
main reason I got this was for easy moving around my small studio space when patching etc - and the wheels are strong and smooth, so really happy with that too.
I had a pretty decent 2-tier z-stand before by Hercules, but the Jaspers really is a major step up.