Let me divide three kind of arguments.
I have to quote FRIDGE here and, indeed, this application has serious usability problems, Seems as it was designed by someone not used to the RSS world and use.
A GUI is not eyecandy only but an effective and down to the task at hand design. Good icons, beautiful details are welcome, we are all on a Mac after all, but all these must adhere to a logical process as it can predicted by simulations of everyday use of the average users. This is the center of users centric design.
This applications lacks all of these above.
You can't see, immediately see, which news are new. The simple red pillow is something good on a page with 3/4 elements but it pass by unnoticed in a page full of articles. A bold headline, as newspaper, could be a better sign.
You have to read the news before the refresh cause there is no way to keep them in a unread status between session.
The refresh and mark as read task is a All or None matter. You can't refresh or mark as read a single page or article. All or Nothing. Stupid (sorry but it is true).
Read the review below for further strange behaviors.
Maybe the next updates will change something of these but right now you have to deal with it in a current state and pay in the hope of changes.
It consumes after a fresh start 60MB RAM. After an hour of activity, it pumps up at 140MB RAM. This is simply unaccetable (NetNewsWire eats 23MB RAM). C'mon it consume more RAM than Photoshop with a full website mockup loaded!
Oh well! It is the price the Dev choosed so stop complaying. In my opinon it not worth of the price requested BUT, at a lower price AND in this state, i still will not consider buy it, so...
ps. Don't try to Trim The Fat (or Xslimmer it) from this application. It will crash on startup indefinitely.
psII. Stability wise, on my Machine it worked fast and well (MacBook last gen with 4GB RAM and Leo 10.5.2).