Honestly, other than dreamwidth (and the like), I just have a wordpress blog with Akismet for spam protection. I haven't used Blogger, nor do I know what their back end looks like.

But it seems to me that the more means of access you create, the more possibilities for exploitation by spammers. Exploitation meaning any which way.

But I'm still in favor of greater access. One of the things I really love about dreamwidth is its commitment to interoperability and inclusion.