Yeah those Plugins are great. Me for example I love the Kotelnikov (Bus and Mastering Comp) since it has a peak - crest function and 2 Release times. 1 for the Peaks (those you can detect with the peak - crest) and one for release times. In conjunction with their "Delta" - Button you are able to hear JUST the things that get compressed by the compressor. So its really easy to work with it and you can make cool musical pumping - fx.
They also have pro versions of their plugins, but I see no need to upgrade since they are perfect.