[cheat-master30]

I use version 3.7, because it suits my forum and my members like the features. The reasons though that big boards don't use 3.7 is likely because either:

1. They've modified the board to almost unrecognisable degrees for various features and style stuff, and it'd be a massive undertaking to upgrade, and either they can't be bothered or are slowly upgrading their forums.

2. They want mega simple features and such like.

3. License expired and they're using an owned license? Or maybe they just really don't care about the software because keeping the forum running is enough to worry about.