So I went and installed and played with a ton of SEO plugins. My conclusion: hardly any of the new ones are original or truly add value, but they all promise heaven. The more well known free SEO plugins, including my own, have mostly overlapping feature sets, with some of them having features that others lack completely, and code quality varying highly. Some WordPress hosting companies complain about SEO plugins in general, having seen quite a few of them now I understand at least where they got the idea that SEO plugins are slow. I guess the burden is on me to show that my WordPress SEO plugin doesn�t suffer from that slowness.
Luckily, I know some hosts make people move over from other plugins to mine, and I know for a fact that this migration guide on my blog is highly visited because people get complaints from their host about All in One SEO using too much resources and wanting them to move to my WordPress SEO plugin. Some other people still swear by AIOSEO though, which is, of course, fine: to each his own. ajmalseotips.blogspot.com