The panels do their job, but I had problems after one year when using velcro wall adapters. The black fabric on the back of the panels started to "detach" from it, which caused my panels to bend forward, and after a while fall from the wall because of the weight.
After having contacted EQ Acoustics customer support, they told me there was nothing I could do but purchase a spray glue to reattach the fabric on the back myself, so an expense of around 10+$ on the top plus some DIY to fix the problem.