Wow... that's a lot to digest.... Let me hit on a few points asked. As far as much less work, that would depend on how many circuits one is going to use. I got the VP-X pro, it has I believe 27 circuits, and I use every bit of them and more. Now if had to drill and connect 27 + breakers and all the busses to connect them, yes that's lots of work and lots real estate on a small panel with dual glass screens. Installing one VP-X box takes little work. Next, wiring control switches is with small 22 gauge wire and all the switches have a common ground, again 22 gauge is more than enough. All the heavy gauge wires go to the VP-X not the switches, the side effect is switch life. Setting up the current (Amps) for each circuit is just a program setting, if you need to change it you don't have to remove a breaker and stuff another one in it's place. You build your panel and forget or add another circuit, no problem, no drilling or figuring out where to connect it. Next, back up power, the VP-X monitors a backup battery and you can run this backup outside of the VP-X (I do). Next, it locks out your starter once the engine starts, it connects to you trim servos so you don't need a relay board and you can slow them down as you pick up airspeed, it runs your flap motor and allows you to program flap degrees and one touch full up flaps, monitors amps per circuit on the EFIS, full control of all the circuits on the EFIS, displays an immediate fault on the EFIS, reset on the EFIS, backup battery voltage on the EFIS, circuits on/off status displayed on the EFIS, built in overvoltage to the field with alert. And much more.. Can't remember all of it, and it's not just bells and whistles, this is useful troubleshooting info. On the contrary, breakers/fuses do none of these features. BTW, the VP-X has multiple redundant grounds, it does not rely on one (since you asked).
I totally agree that these are not for everyone, it does require some electronic abilities to install properly and getting the most from the system and you do need a good EFIS system to use it. And they aren't cost effective for some, either. But with all that said, they are very reliable and the same failure points in an aircraft still exist with or without the VP-X. The battery goes to the master relay than to the VP-X, any failure before the VP-X is still there, relays and master wiring do fail. The VP-X can be bypassed for emergency power and it does not affect the VP-X system.
The only way you can compare a old breaker/fuse system to an VP-X system is to actually install one and use one. As you can see from VP-X users they would never go back and I agree with them. I've been down both roads and there is a very big difference between old and new. And as I said in a prior post, I knew nothing about these systems when I was offered the opportunity to install one. It was a bit foreign to me even though I have a lifelong electronics background, I design and build a lot of my own goodies for aircraft, but it seemed like a great idea and something new to try. I am very pleased with this product, unlike many other products, and I'd never go back.
I'm not trying to get anyone to buy one nor am I slighting breakers or fuses, this is on a level of it's own. Like comparing steam gauges to an EFIS system. They both do the job, they both have failure points, they each install differently. But they each have very different features. It's each to their own for sure. Mark designed a very powerful, full featured, reliable electronic circuit breaker system and it flat out works. High power MOSFET's are a tried and true technology. I've put 4 years on mine and not one hiccup. I wish I could say that about everything else I've installed.
If I forgot to answer any of the questions or concerns I'm sorry, there's plenty on the posts and I certainly don't know everything about the Vertical Power stuff... Hope this helps.