At 650 posts a week, I don't think that feed is highest rated. I've clicked plenty of articles from the feed that are low rated or brand new.
I wish there was a highest rated feed - the default feed is way too noisy.
don't think there's an RSS feed for that :/
Take a look at Mozenda.com
I was using them for basic scraping, but I read on their site that they have an extension to turn what they scrape directly into and RSS feed.
Hope that helps.
I have written a screen scraper for the page in ruby. Mail me if you want it. You might be able to generate a feed from that.