RSS does *exactly* what an this app reader is SUPPOSED to do. It's not like any of those fancy "readers" that just shove a whole bunch of curated content that you don't care about in your face (you know which ones I'm talking about). You import your this app feeds of choice, it fetches them, end of story. As someone who is currently trying to migrate from the dinosaur that is Opera Mail, this is an absolute godsend. (By the way, importing from Opera worked flawlessly! Thank you for implementing OPML *correctly*!)
My only criticisms are that RSS doesn't integrate with Safari to fetch this app URLs from sites that offer them, which would be enormously helpful, but probably difficult to implement, and there are quite a few spelling mistakes in the interface (I'm assuming the developer's first language is not English).