No real new functionality

Besides support for a few new codecs and a slightly simplified GUI, theres not much to speak of here.
The one reason that I bought this app is that I can use it across 5 computers now, and saves a lot of money in my production studio.
Also, it doesnt have the new look and feel that Final Cut Pro X and Motion 5 has, not that Im super thrilled about those either.

Ken Oak about Compressor, v4.0