I used these to mount a pair of EQ Acoustics Spectrum 2 L5 Tiles to the roof as a cloud.
My hands (metal industry, both workwise and musicwise (haha) for about 40 years) were a bit too thick for me to be able to mount the hooks according to the instructions myself (which is why I only gave 4 stars for quality, i.e. not really bad) so I had to bring in help from someone with nimbler hands.
Apart from the above "problems", mounting and construction are excellent, whether they will hold only time will tell - but I see no reason why they shouldn't.
For me the hooks could be a bit taller, other than that I have no complaints.