Of course, this depends on a lot of factors. My experience is with feeds. Feeds is *designed* to deal with periodic imports and handles updating of records based on a UUID (unique id). Migrate is more designed to be a "one time" but highly configurable "importer." The source for Feeds can be dynamic, but I'm not sure about migrate.
From my experience, I would say Feeds could handle this job very well. My guess is you could make migrate work too. Migrate has lots and lots of code flexibility and many people complain that feeds can be very finicky. 
Try both or stick with feeds as it was designed for this kind of periodic import.