Lately I've been trying both babel and polyglossia against each other to see if there are any advantages either way. But to my untrained eye there is no significant difference in regards to output between the two.
While this post is giving a good overview on the status quo I'm interested in the current "trend":
Where is the future going? babel or polyglossia?
datetimeanddatetime2. – cfr Aug 30 '15 at 21:01babel. – Alan Munn Aug 30 '15 at 21:10