I'm late to the party, Jeff, as always. My opinion probably doesn't matter, but I don't have any issues with the native commenting system. I use single plugin to stop 99.9% of the comment spam - WP Conditional Captcha, which only activates when a comment is flagged as spam by Akismet. Because I use Nginx instead of Apache, I drop all connections from known spam ranges (vs. deny) when they try to comment, without affecting other access.

Well, I actually do have one issue. Very few people comment. I attribute that to Google's animal updates - only spammers use keywords as author names anymore. People commented all the time on an old blog, when keywords weren't an issue. Non-keyword posters did too, just not as often.