Use this for my daily driver when eating at the desk or otherwise doing something where I wouldn't want to get the keyboard dirty. Much easier to clean.
I don't use it often as a dust cover, but if you're diligent it works well to mitigate dust.
The 65% version fits my alt very well. I will say the edges are "sharp" but it's acrylic so that's to be expected. For the price point it's a great purchase.
I can't vouch for other sizes, but the 65% fits my ALT V2. I am content with it.
It is "sharp" around the edges, and these edges come to "sharp" corners. I use quotations for obvious reasons, these edges aren't that sharp/pointy. The flaps of the single-sheet of acrylic are not fused together, and while not flimsy will temporarily dislocate under small applied pressures... all this is to say that, if you are so inclined, you just as well could go to the hardware store (or order online) a sheet of acrylic, cut and form it to your spec for the same or less, AND you wouldn't have the logo and could choose whether to smooth out the edges and corners (not a huge time commitment). Am I going to return this and opt for what seems to be the equivalent DIY construction? No, and these features don't really bother me as they once did... 2 months later, in all practicality I like it, including the way it looks, and it's nice to leave my kb for any length of time and return to it dust-free (not to mention help with general wear & tear). If you are not so inclined, as apparently I was/am in this case, then I'd recommend picking this up, at least if it'll fit your kb (like 65% size for ALT kbs) and you've got some Drop ca$h to spend.
I bought this to fit my LOTR TKL keyboard and it is about 1 or 2 mm away from useful.
Either it sits awkwardly on top of the keyboard or it fits one side and not the other.