Could someone else please explain what Prochannel is, and how/why it's plugins are different from a Vst? 

From what I understand, it's meant to provide a more hardware-like channel experience, but it gives a lot more than that.
 
From a pretty good SoundOnSound article:
 
"Why have both a VST FX bin and a ProChannel? Well, the main ProChannel advantage is workflow; its effects are consolidated into a single channel strip, like the hardware mixer model, rather than spread over multiple open windows. Perhaps more importantly, you can save a channel strip as a single preset, as well as mix and match modules to create an all-Cakewalk channel strip, an emulation of a classic SSL console, a combination of the two, or something more à la carte — and have different strips in different channels!"
 
So yeah, there's not a great deal of difference fundamentally, but it's a great workflow enhancer. It does a great job consolidating the plugin UI elements in one place and gives you the ability to create presets and it can use fx chains. Pretty powerful stuff.
 

I've always looked at the Pro Channel as like a desk.
every desk I have owned (hardware / mixing board) has been unique in its sound characteristics.
to me the pro channel is like a console strip in any other board. it has its uses for something and other things...well use something else. I use the QC EQ on almost every track not just because of its convenience but also because of its versatility.
 
owning a good desk is key in recording music, own a good virtual desk in these times we live in is even more important.
The Pro Channel allows you to use this section to fine tune, add some base effects, then use your own / supplied plug ins to add more detailed effects. this is where you find the keys to success.
 
I also find the balance load on CPU usage, using Pro Channel to be really smooth and less taxing then 3rd party FX.
 

Click the link below and view a list of YouTube videos to watch about Pro Channel. 
 
You will know all after watching them
 
Pro Channel  Videos
 
Enjoy,

ProChannel, unless they've changed something, is just your garden variety VST designed to fit visually into the ProChannel pixel width.  There is nothing functionally different for sound, tho some ProChannel vsts, like some of Softube's, lose buttons/functionality because of the screen space.  3rd Party ProChannel VSTs usually come with both PC and regular versions.