I think it's almost impossible to rate a handwriting app, expectations and uses can differ so much between people. But you may be right about the general quality of appadvice's reviews. I can understand their point for rating Notability better than Noteshelf, but I can't get over the rating of Paper as an essential app. I don't understand why this app is so overrated, it's been several times in Apple's recommendations too. The ink rendering engine may be good, but that's all the app has to offer. The rest is poor and expensive.
I reinstalled Notability for the umpteenth time, and I must say I was impressed by the quality of the handwriting. It flows more smoothly and looks better than in Noteshelf. But it still won't replace Noteshelf, because the interface keeps getting in the way of my writing flow. This is the real reason I can't give up Noteshelf. It lacks many features that could be useful and that other apps have, but the one thing it offers is essential: an uncluttered and efficient interface that lets me just write my thoughts.