This apparently helps improve your page rankings .I know nothing about SEO (Search Engine Optimisation) so I will just say this its free and when you search for My WordPress (yes there is a space after My) using Google and selecting pages from the UK  this site appears at about 8 or 9 in the results(on 14/07/2007 @ 2010hrs).Not bad when you consider this site was only registered on 7th October 2007 .Try searching for MyWordPress with Google No 1 as of the date of this post!!! 

So I beleive that this plugin with this theme is pretty damn good though who really knows.