Having had a few requests for stands on wheels I decided to buy a set of these for my manfrotto 126BSUAC light stand. When assembled, they are fine, but I personally found attaching them more awkward than I expected. The one tiny grub screw to secure them wasn't very reassuring. And actually failed on their first load in/out, when 2 of the 3 wheels fell off after a bit of banging about.
This is in stark contrast to my Avenger A9000NB wheels which are far easier to attach, far more secure even without using the screw to secure it!
Now, I still give them a decent rating because, when assembled they do work fine, and give my stands some extra functionality.