I had a fairly smooth setup going with version 6..... Just email dramas.
Seemed more than stable.
I couldn't believe how fast it served the forum. I was amazed lol
The worry was building out the forum then it come unstable once too many users and posts clogged up the system.
Seemed fine with basically no posts and 3 users on at once. PM etc was all fast.
Using a cloud system to build it all out for now. Once I get the backing up and restoring all sorted I'll have a look at moving back to the Pi. Extreme Noob. Still haven't worked out or researched backups lol.