I am an rss2email user myself, and I fail to see what it would lack compared to say, Newsbeutter. If what you want is something like Mutt, why not just using rss2email and keep using Mutt to read your RSS feeds as well?
You get features like tagging/sorting/filtering "gratis", as you already have it in your email system. If you use IMAP you automatically get the "centralization" feature of things like Google Reader. If your email system allows you to read emails offline then you get it implicitly with rss2email.
When I think about all this I wonder why anyone would not want to treat his RSS feeds just like his good old email :-)