We have the MMO-kit and it’s a nice kit. As a learning project for people new to UE4 and interested in MMO games, it’s probably the best out there.
However, it hues to convention and we quickly determined that its framework would not be suitable for our game. For example, our quest system does not follow current convention at all.
It has proved much more productive to build our systems from scratch.
If we don’t run across a positional voice chat solution, we’re going to use the MMO-Kit’s separate chat server but in that case we are almost certain to use Pirate’s Social System front end.
The central pivot of our game at this point is the ARPGIS, though we have extended the internals considerably, and nearly every system we have interacts with it in some way.