We have been using it for almost 4 years non-stop. We have 4 devices in a detached house with a garden and they are constantly in operation. The only thing I can say, which I believe applies to all these liquid evaporators, is that the steam leaves a greasy residue if you have a frame above the socket exactly.

It lasts for a month if you leave it continuously plugged in. I didn't see any mosquitoes with the balcony doors constantly open.