What are my takes on this. Let's see.
As someone who does a lot of word puzzles, and has for decades, I found the daily puzzle and the first couple of levels pretty basic. A lot of words like "ARO_ND" where there was only one option; a handful where there was more than one and it just needed to wait to see what letters got eliminated.
I didn't keep playing after the first two; I was curious to see what harder levels looked like, but not curious enough to play through potentially a lot o easy levels.
The main problem I noticed was that a given letter and a filled-in letter looked identical, so when I did have to go back and change something (I'd mistyped the "U" in the above word for an "O", as it happens), it was hard to see which letters I'd added and thus which ones I could change or remove.