I just got this yesterday so I may be updating this review as I use it more. My initial feeling is I like it. Its much nicer to draw on using the Apple Pencil (iPad Pro 2020 12.9"). I've read several reviews that you wear the tip off your Apple Pencil rapidly with this product. That may be so, but they are fairly cheap, so I don't think it would be a big deal if you really enjoy the experience of the paper like feel.
Installation is super, super simple!. I've never been able to install screen protectors without messing them up. You get everything you need to align the protector, clean the screen and smooth it out. Check out the video here on the Amazon site.
Now the bad news. If you use a protective case like the UAG Metropolis, this product will not work unless you trim the screen protector. These type cases fit snugly around the corners of the iPad and will pop the screen protector off when you try to install it. I had to trim mine with a razor knife and it looks a bit funky. This required me to lift the protector off to trim the edges and I got a small piece of crud under there and now have a small bubble. As it is, this screen protector fits almost exactly on all the glass so it's hard to see when installed in original size. When you trim it like I did, you definitely can see it. I trimmed mine more than I had to and once I'm convinced I really like this product, I'll install a new one (I suggest you buy the 2-pack for only a few more dollars.
I have not used customer support, but based on the comments in the ratings they seem very responsive to customer problems.