Was the forum actually good back then? Or was it the same bug-ridden, badly managed mess that it is today?
Bugs were always there. Unfortunately.
As for whether the forums were good... During the time Michael did the job of CM, the forums were excellent but not professional. They were close-knit, intimate and personal. Someone got bullied, they made an announcement against bullying. They really were that close back then. Seth professionalized the forums. A much-needed process as the game grew. Unfortunately, he also managed to drive off the old team of mods, which got increasingly demotivated and inactive.
The result of this was a lowering of standards and, combined with some other factors (the forums got less game-related, spam rules at first were so tight most of the funny bits were squeezed out, then so loose no one could try and post a topic without having it driven off to worthless rubble, the other sections got a complete lack of attention and no effort whatsoever to give them relevance) the old community degraded consistently.
The old community had its flaws, but we originally had over 4(!) forums per world to discuss the game, no era passing by without discussions about possible winners, community-drawn maps and possibly power charts, publicized plans and diplomatical drama. On top of that we had a great casual community that combined light roleplay with british and american comedy with a touch of sexual innuendo and a hell of a lot "in-jokes" and rules.
As time passed, it perished, things got worse and worse. Ronelm came and pretty much scared off what was left, since it's been like this pretty much.
Worse really, the forum now at least has an active staff team and a decent amount of posts again.