I have no experience of Drupal forums, so it's hard to comment. However, I've thought about this in the context of forums used at work, and I'm cautious about your idea.
For me, the major forum packages (phpBB as here, SMF as on
YACF, VBulletin as on
socal bike forums) are not major by accident. I don't think there's much to choose between them but, if looking for an alternative, I'd want to think hard about whether it matched them in:
notification facilities, moderation (inc. banning, moving threads around), ability to structure hierarchies of topics, private messaging, other thread management (post of the day, FAQ building, sticky threads/locking topics to the top of categories), editing facilities for thread authors, protection against spamming, RSS, mobile device integration (Tapatalk etc.), polling, statistics, handling of old threads, and so on
None of these may seem important individually, but I would expect a package lacking them to get frustrating. I don't know what Drupal forums has.
If there's an API, and/or possibilities of using an external authentication data source, then combining log ons with other systems is still possible. So is getting lists of current postings. Or could you do it from an RSS feed?
Drupal may still be the way to go, but these are things I'd want to check.
ForumMatrix doesn't cover Drupal, but its list of points to compare on may be useful.