[@rebootnow Participant 16 years, 3 months ago]

My reasons for deep integration generally fall into two categories:

A: niggly issues like the fact that I couldn’t get WP and BBP to share the same nonce value for safe logout. These all magically go away with deep integration (e.g. I now only use WP’s login/logout functions).

B: it is much easier to create a custom user experience that crosses from blog to forum. My biggest example here is a site wide reputation system. So I need to display display profile pictures, badges and levels alongside forum posts and blog comments in the exact same way. I could do this without deep integration but then I would need to duplicate some functionality across WP and BBP plugins (e.g. writing a function on the bbPress side to get the avatar location).

I think at its core deep integration is about a trade off between [raw performance + server cost] on the one hand and [dev cost + ttm + maintainability] on the other.

So to your second question… the data I pull across is mainly user metadata as I described above.

And regarding plugins… very few plugins that aren’t custom.

One other thing: the deep integration we’re talking about is one way. I also integrate the other way (e.g. showing forum posts on blog pages) and this is done without deep integration. That is, I have created functions on the WP side to query the db for forum data.