After having 2 airplanes wired by 'avionics' people and had problems, we used the Approach Systems Fast stack for our 7.
Garmin 327,430, King COM,Garmin Txp plus Digitrak.
Plugged everything in, switched on, it worked - very happy indeed and about the same price as getting someone in.
Work quality varies greatly. An "avionics" person who just simply uses solid work practices and the proper tools will put out a quality product.
People who don't follow tool manufacturers' instructions or acceptable practices create a lot of problems.
I recommend, if you work in the aviation field, go look at the backside of a circuit breaker panel on a Boeing product. Go down and look in the avionics bay.
You don't have to be an "avionics" guy to do a good job yourself. You just need to have a solid plan, use acceptable practices, and use the proper tools correctly.
The hub system is throwing extra money and complexity at a problem that just doesn't need to exist.
I like the idea of the Vertical Power system. From what I've seen, its an exceptional product line that adds real value, for a price.
But, you can get quality results yourself, doing it old-school. And, you can save money and weight in the process.
I've wired a couple of IFR panel upgrades on some older flying club aircraft. The learning curve (even for an old "avionics" guy) was steep at first. But, its doable.