Sin que sirva de precedente voy a copiar y pegar una entrada en el foro Wiki de moodle en ingles, pero es que me han tocado los guevos ya!
I've been reading so many times that there is the feelling that NWiki is cool but is not stable. I'm sick of it.
THAT IS NOT TRUE
Check this forum, and see the reports: NWiki is stable and never loses data nor fails to deliver functionality.
The issues that has NWiki come in the installation/migration process due to literally hundreds of possibles scenarios (versions of moodle, databases, php, and fancy uses of wiki (groups, student, visible, separate)).
We have been dealing with this problem for a very long time. And is NOT a problem of coding using butterflies (I'm sure Sam does ). Is about testing and testing and testing, and then test a little more. Is about working within the community, giving support to users day, after day, after day, after day.
We have in our backoffice the testground to migrate wikis. Lots of users have sent their backups to us asking for help which they got.
Our stability comes out of heavy testing for a LOONG TIME.