Interesting Insights about Hosting, Performance and SEO

I recently made a blog post on how performance issues on your website can effect, eventually, your SEO for a site. Its had positive reactions from people, and I'd be very interested to have input from the community here about their experiences.
One question was "what settings work the best on the server or at least the most important ones, to give a Joomla site the strengths it needs to compete well in this area?"