The problem I've found with aggregating multiple feeds into a single chronological stream is that some feeds totally overwhelm others because they publish more frequently.
If Feed A publishes 10 articles a day and Feed B publishes 10 articles a year, the articles from Feed B get totally engulfed and pushed way, way, way down the list... effectively they become invisible.
My aggregator limits the number of items by feed and by domain. The problem is less of an issue if you add many more feeds and filter harder. Those rarely publishing do still get drowned out but it gives you plenty of other things to read. Thanks to volume, at times, if the slow publisher posts something awesome (they often do) it is reposted by the more spammy domains.
I do have other ideas to fix that issue but the ink is still wet on those.
If Feed A publishes 10 articles a day and Feed B publishes 10 articles a year, the articles from Feed B get totally engulfed and pushed way, way, way down the list... effectively they become invisible.