Apparently I'm a more casual reader than many - I use it to read my feeds *when I get to it*. It seems many people place a much higher priority on their feed reading, and need alerts and widgets.
The biggest thing I miss (when compared to the web browser interface on Android) is the browser would display articles 15 at a time, allowing me to easily read the ones that caught my interest, and mark the remainder of the 15 as read without touching the rest of the articles in the feed. This allowed me to whittle away at my reading list. In the app, the only way to mark something read without affecting the entire feed is to open the article.
I'm not sure, but I think this has an adverse effect on my "recommended" list, as it thinks I'm reading things that I otherwise wouldn't have read.
The only reason I stick with the app is that the web interface routinely misinterprets where I have clicked - selecting the wrong feed to open, or opening a new email instead of marking all items as read. Since I don't have this problem with any other app (or even any other web page), I have always assumed it was an issue with the web interface for reader, but I could be wrong.