Trying to play catch up, so only quoting the most recent quote.
Couple very important points to make.
These companies may be small, however the regulators are currently being manufactured by quite large entities. The same entities that make most of the regulators for Huish, including parts for Atomic.
If Deep6 went away right now, you could still get parts kits for all of their regulators via Apeks, HOG, DGX, and a slew of others that are using comparable/identical parts kits.
HOG is essentially the house brand for the largest dive shop company in the US, so as long as Divers Supply doesn't go anywhere, HOG won't go anywhere.
The size/financial stability etc etc of WMD and ODS is arguably better than that of most scuba brands as they are not tied to any particular brand. They make regulators, and they make LOTS of regulators, for many people. I would argue that they are in fact more stable than companies like Atomic, Oceanic, Hollis, and Dive Rite. Hell financial stability of Atomic, Oceanic, and Hollis were the reason that they were sold to Huish in the first place.
In terms of quality, the machining tolerances and what not are on par with anyone out there and in many cases are better than some of the "big boy" companies, particularly in the plating options where companies like Apex are very restricted on the types of plating they can use since they are in the UK.
In terms to parts availability, it is expressly written into the dealer contracts in North America for all of Huish's brands, all of Aqualungs brands, and all of Scubapro's that parts kits are not to be sold to end users. That is the case in many/most other regions as well. That alone is reason enough to start looking elsewhere when talking about technical diving regulator options.
You do mention
"The tiny/diminutive start up companies sell parts and tools and expect end user to do the servicing because they don't have the distribution network or the financial bandwidth to do it through their own dealer network or themselves. They make up for their shortcomings by putting the burden and risk on the consumer. They make the "defect" appear as a feature and an advantage."
What about Poseidon who is embracing the concept conceived by Chris while he was at HOG to not only allow end-users to repair their own regulators, but to actually have agency approved courses to teach them how to do it? Dive Rite did not restrict access to parts long before that, though did not have a course for end-users because the demand was there by technical divers and they didn't want to restrict access. The large companies are protecting their antiquated dealership models by making that restriction. I would trust a borrowed regulator serviced by an individual who is actively diving and depends on those regulators for his own life long before I would trust it when serviced by the random Scubapro shop in the middle of a land-locked city who only services a handful of regulators a year. Hell, Air-Tech scuba is a business dedicated to fixing regulators from local shops because it's easier for them to not have to deal with it. Scubatoys and others have done contract repair service for a long time because of that same issue.
Now, I will agree that recommending brands like HOG and Deep6 to someone who lives in Asia is not where I would normally go because of their limited presence over there. If it was a dedicated tech diver who is doing to do their own service and is looking for something like that then I wouldn't say you should avoid those regulators, but they would not be my first choice. In the US however, I think the technical community should actively avoid brands like Atomic/Apeks/Scubapro for technical diving regulators because of their service issues in this country. I don't know what their dealer agreements look like in other countries, but I know several dive shops in the EU have lost their dealership with Apeks when they were caught selling parts kits to the US. That is especially compounded with their ridiculous pricing in this country.
Deep Sea Supply and Salvo came up, but did the regulators that were made by big stable companies come up that are no longer serviceable? The big brands discontinue support for products regularly and you never really know when or what is going to go away. If you want, Salvo regs are still quite serviceable, just not with parts kits from Salvo directly. They are still standard regulators from Taiwan that are still manufactured and you can still get parts for them, just have to look. No different than we have to do for parts for the older Scubapro regs. It's annoying, but if you're committed to keep the going, then you deal with it. No manufacturer wants these things to last forever, they need you to upgrade, so stuff goes obsolete.
@LanceRiley I usually don't respond to these big threads unless I get tagged in them which is why I'm here.
You have perfectly good regulators right now, and I would recommend keeping them. You may or may not be required to dive DIN, but if you are, then my recommendation would be to purchase something from Scubapro and also purchase the DIN conversion kit for your existing MK17. Learn to swap them back and forth yourself, or buy a beer for your friendly local technician to swap them when you need to. There are merits to both styles of regulator, but I would not look at switching brands since you are already invested in a perfectly good regulator and switching brands is only going to prove annoying for you. If you purchase a new first stage, I would consider looking at the new MK19 from Scubapro since it is a sealed diaphragm and has a swivel turret which I feel is better for hose routing, though it admittedly looks quite goofy. If you find a good deal on a used MK10/20/25 in DIN, then that is perfectly fine as well, just make sure to soak it after rinsing to prevent salt from getting into the piston chambers and staying there
