Roundups are great and please keep doing them!
Quality counts. So does highlighting old plugins that may have been superseded by a better one/way of doing something.
Certainly, I think it good idea. The qualitative content is that, for what appreciate your magazine.
Good if they are poperly curated and if you can interweave your own hand's on evaluation and examples.
The roundups are one of the best and most useful features of the site - please keep them!
I read Smashing for the content. A GOOD roundup is a good post and worth reading. But the majority aren't. So long as they are thoughtfully written and are relevant (ie. up to date, about current trends, etc) they are worth reading.