I think the powercore is least desirable of all the above.
I just don`t like the plugins and economy wise I don`t find it good value.
Liquid mix is a sintefex device that only processes the algorythms rather than actually being able to create new ones from kit, so it is a very very accurate machine for the reproduction of real gear as it actually takes volta kernals to from the real devices it emulates.
The compression and EQ is about the best I have heard from "software", with the exception of Nebula processor, which just tips it as the best due to the wa it captures some of the air and open-ness of great compressors.
UAD I think is also very good for some plugins, although the compression still seems to be just behind the liquid mix in how the compression behaves.
It`s worth it though for the amount of great plugins you can get.
Both are fantastic additions to a workstation.