IDM Splits a File into Pieces and then download it
+1 Damn True!
Every DM splits files into pieces and then download, also each one of them have resuming capabilities provided the server supports the same.
Not exactly. If connection is interrupted then Opera restarts the download many times while FDM resumes.
FDM also does that.
I think there's something about utilizing the max available bandwidth, which from my experience IDM does best. Same goes for torrent clients too, I think. Not all of them download the same torrent at same speed. Of course, you are ultimately limited by your connection.
Also IDM's footprint is lower and integration with various browsers is tad better. And frequent updates ensure little problem with newer browsers including alpha, beta builds.
That said, FDM is as good as it gets, and with a better feature list too. And above all it's free.