RSS Aggregator Question

This is for all the people who use an RSS aggregator like bloglines or something.

When you guys look at your feeds do you tend to just look at the new ones only or do you look at the last 100 or whatever? I know this depends on when you last checked the feed.

Basically, do you find it useful that they archive all the past articles? Would it simplify things if they just listed the recent ones and didn’t archive all the old ones?