Just wanna chime in with the discussion. We are using Appvolumes for about 3 years now and started working with in in Cloudvolumes version 1.8.
We started with appstacks only and after a while started using writables.
We have had our share of interesting bugs along the way.
As fdrietatns says I really like the product and the ease of use. That has always been it's top selling point. But fact of the matter is that it is easy to learn hard to master. If you don;t knwo what is going on and what the application is actually doing it is quite hard to get a grip on it. I do believe that version 2.13 is quite stable and quick (mostly due to reverse_replicate adjustment). But as with every product, you win some you lose some. The biggest issues we are having is mostly with writable volumes. From time to time we need to rest it back but have implemented UEM to at least save basic configuration for users, this works quite well.
If you are trying to merge from persona to Appvolumes without losing data and everything needs to always work 100% I do believe you should not try to go to Appvolumse. There will always be something that will not work. Because the writable has a local profile it is hard to migrate personal data. Only option here would be UEM, you could give that a try?