OK, so I've tried the Wakka, Wiwi, and PHPWiki modules (I think there's even another I tried along the way that I don't remember the name of). No single one of them seems to have good ACL (like Wakka) and great editing capabilities (like Wiwi) combined with good modularity (like PHPWiki).

For the serious Wiki crowd, what's the answer for Xoops+Wiki? Are people using stand-alone Wiki, or quietly wrapping one of the major Wiki's in XOOPS pages? I've been diligently searching the forums and there doesn't seem to be a great answer...