When I select a material, a nice big quick view appears on the side, which is a great thing, because here you can normally see what this texture actually looks like.
This is one of the best user experiences in TM. 
The problem is where these quick views do not appear, e.g. at Quixel Megascan.
I can see the patterns on the side, which are spheres (why spheres at all??? we'll come back to this later) but these textures don't have a quick view, I should see what it actually is on the shape of a small sphere.
Moreover, these patterns are often hardly distinguishable from each other.
You have to download it (which sometimes doesn't even work for me, you have to restart TM to make it work again),
then put it on the interface and try them all one by one to see what image it shows.
I'm very happy with the Quixel Megascan textures, but something needs to be done with the quick views, because it's very slow and cumbersome.
If you check the surfaces in the Quixel Megascan's webpage, you can see, how big the quick view of the same material:
