I just switched from Roll20 + Demiplane to Foundry. Demiplane's adversary sheets are still very much in beta it feels like. You can't create brand new adversaries for example. It's a weird omission because the Demiplane implementation is the only way to use DH on Roll20. Likewise, modifying existing adversaries is slow and clunky. For example, you can't delete adversary features, and while you can create new features on existing adversaries, you can't implement any rolls in those abilities, just plain text. Also, it's kind of bizarre how when you write in the text box on an adversary sheet, the input of the text is delayed, as if it's reading it in real time. It makes it difficult to write longer pieces of text -- like when you want to create a new feature or an ability...
All of that coupled with the occasional log in issues that the players have had made me look into the Foundry module. It's definitely better all around, and much, much better as a GM.
Roll20 has kind of bungled the Demiplane integration. They're using it with all the new games but it's just not ready yet and it's much clunkier to use than simply having the game on Roll20. They also messed up the D&D 2024 sheets badly. Roll20 needs better project management.