Yes, there is a difference. Initially I didn't use the PC4k channel compressor that much, but, having spent some time playing around with it, I now really like it.
I wouldn't want to be without it. It sounds/works differently to the other PC compressors, but just took me longer to set up well. The gain reduction LEDs aren't much use, IMO, so you really need to use your ears. I probably don't use it as often as some of the others. Having said that, it works far better on some material .