My regs are all made in Italy.they are manufactured by an OEM in Taiwan, along with most every other reg out there, including some that claim to be "Made in USA"
Anyways on topic. I have a set of Deep 6 regs (I really need to dig them up and put them on the classifieds). I think from a performance standpoint they are about equal to most regs on the market, breathing similarly to all but the overbalanced regs. And it is hard to beat getting a sidemount set for about $800 (in 2019). If you want to service it yourself, the kits, training, and instructions are readily available.
The negatives is that they are a small company with a very very limited dealer network. So if you don't want to service it yourself you best choice is to send it in. Which is fine if you are in the US because their turn around time is quite good, often little more than a week door to door. But outside the US, due to travel or living, it will be a concern. It isn't like with some brands where you can't swing a dead cat without hitting a dealer.
So quality gear, but the direct to consumer nature means the support might not be as robust as other brands. So you decide what is important to you. I personally moved away from their regs as I wanted a better international support network. I want to be able to drop my regs at ZG and pick them up the next afternoon.