Selfhosted

What you need to be aware off is that the LibreOffice based options run a full headless LibreOffice client on the server for each connecting user and stream the view as tiles to the webclients. If you mostly use low power devices to access your office files remotely this can be great as it offloads the processing to the server. But I think in most home server or VPS settings the server speed is the more limiting factor.

OnlyOffice on the other hand runs entirely in your browser and thus puts little extra strain on the server.

OnlyOffice has been working fine for me though I've not used it in serious capacity.

I initially started with Collabora but for some reason I couldn't get it working. This is surely not an issue with the product though and entirely my fault.

Nextcloud Office (aka Collabora) has been the nicest in my experience.

I came from google drive. I did a google takeout of my drive contents, dumped it into nextcloud, and every document so far has opened without trouble.

From what I can tell, OnlyOffice has the best compatibility and the nicest UI (similar to MS office), same as with the regular applications. NextCloud Office is based on LibreOffice (officially Collabora, which is their name for the web product), so again same as the regular applications you'll have some compatibility issues. That said, if you don't need compatibility with existing documents or only documents made with LibreOffice, either is fine.

One concern many have is that OnlyOffice is closed source (edit: my bad, it's been open-source for a long time) and russian based (edit: partially russian, see Wikipedia), while LibreOffice is open source.

I used to use OnlyOffice, but switched to Nextcloud office because I like the UI and the documentserver better. Easier administering and the official solution

I've been using the Collabora option for the mastercontainer since the start of the AIO, it's worked well for my users.

What are your requirements?