Hmmm
Yer gona have yer hands full, guys...
Rather than create a fresh "computer vs PLC" debate, let's jump right into VLC (the software formerly known as Steeplechase).
First, it's a bear to configure. The newer version is supposed to have addressed some of this, but I've not used it yet, so I can't attest to that. But setting up IO over devicenet is like wrestling a grizzly.
Second, Citect is the HMI. It is a separate software package that uses the IO database created by VLC. This leads to some interesting confusion, like when you compile the HMI without compiling your VLC first, and get faults, or compile your VLC and forget the HMI, and none of your new controls are on the screen.
And there's my personal favorite, the "oops, forgot to turn off the Clear Retentive Memory check-box in compile options, and just erased 200+ parameters from the system" mishap. That's one you'll only do once, guaranteed...
Now, the good stuff - VLC is flow-chart based, programs in a relatively straight-forward BASIC derivitive, and is sequential. Once you finish chiselling out the foundational stuff from the bedrock, it's pretty nice.
The best advice I can give you is, forget the web sites. If you are using this as much as you say, bite the bullet, pay the money and attend the classes, maintenance and developer. It will save you days to weeks of hair-yanking frustration.
Then again, I'm mostly bald...
TM