Someone wrote a review on how the Mobipocket Reader performs as an RSS aggregator. His review can be found here: http://solsie.com/review-mobipocket-as-a-rss-aggregator/

Pros:

Downloads full articles
Quick downloading speeds
Seamless synchronization process
Free
Ability to create separate eNews lists for different categories
RSS Repository for finding RSS feeds
Newspaper view for PC client

Cons:

Requires a PC with MobiPocket Reader installed
Not all images downloaded to Pocket PC