I've tried a number of RSS aggregators and this is clearly the best and most extensible. I've been able to set up a large number of feeds on my site without any trouble, all of which were easy to style with CSS.
The free version provided much of what I needed, although I opted to purchase the keyword filter add-on. I had some difficulty setting up the filters - not because they are difficult to set up, but because I was using them in a novel way. The support I received was superb and far better than one could reasonably expect for the price paid for the add-on. If you're looking for an RSS aggregator for your WP site, look no further!