One thing, though, Disqus is really good at filtering on-going spam.

Sure. I think once we are up and running and cleaned everything out, we are fine, but I am surprised how limited functionality there is when it comes to admin/moderation. And not being able to delete your data seems just wrong.

BTW I was rendering the side and saw that a lot of comments are attach to a single blog. Could it be that the import is doing something wrong and attach all comments to all posts or something.

The importer did indeed something wrong, but that got fixed. Here comes the discussed limitations into play. I did a wrong import (not surprising since we have to bake the XML ourselves. I expect there will be quite a few more) and most comments got attached to a single post. I noticed it and fixed the importer. However, there is no way to delete this post or alternatively just delete all comments. I can only delete 25 comments at a time. There is no way to rectify the problem (short of deleting all comments 25 at a time). Really, the only thing I can think about right now is to when necessary just register a new shortname.

The import I saw was also showing <div ...> </div> before and after each comment text.

Also resolved. Interestingly my understanding was that comments can be imported as html. I would have expected that the <div> is treated as html and hence not being rendered as text. I changed the importer to just use the inner html of the comment text. Things like <p>, <b>, ... seem to render fine.