I don't use a lot of plugins, but I try out a lot.
This is a powerful plugin with great support.
This plugin's Feed to Post option allowed our main WP site to corral-in some rogue authors that had gone off to make their own site before the main site was completed. The main authors were thrilled to get the posts from the splinter group back under the same roof. Funny thing, the splinter group authors were just as happy to have their content displayed nicely on the main site, without doing any extra work or posting twice.
Does installing RSS Multi-importer lead to world peace? Maybe.
When I had a question about getting something to work in a particular way, the author got back to me (literally) in minutes. Problem solved.