What is the current status of ipv6 adoption in terms of usefulness?
Google maintains an IPv6 adoption page, and there is a per country adoption tab.
Specifically, if I have a network of approximately 300 devices
(workstations, WiFi APs (used mostly for specific industrial devices),
switches, printers, etc) in several locations(currently connected via
vpn) would there be any kind of benefit - from organisational,
administrative or network point - to move them to ipv6, assuming all
the software would support it?
I have already seen questions on Super User and Stack Overflow about people who can only get IPv6 addresses. Also, CGNAT is becoming more common as the ISP run out of IP addresses to be assigned, and you really cannot run services to the public Internet if that is what your ISP uses.
The fact is that IANA and the RIRs have run out of IPv4 addresses, and the situation will only get worse. That is explained in:
Why are IPv4 addresses running out?
At this point, your company should already be dual-stacked (running both IPv4 and IPv6). The transition to IPv6 is not as easy as it may seem, and if you are forced to do it in short order, you will make mistakes. You should add IPv6 to the current network and work through the learning curve and problems before it becomes a requirement. At the Global IPv6 Conference a few years ago, the experts announced that the average number of times a company will change its IPv6 addressing scheme when converting is three, and that can be very disruptive if you are in a position where you must run IPv6.
With the larger IPv6 address space, you will probably be assigned a relatively small prefix (<=32 bits), and it is easy to get provider-independent addressing directly from your RIR, so you will not be tied to a single ISP for your addressing. It also gives you the ability to use the bits for things like region/site/type/subnet encoded into the address. It also simplifies things because each site should be assigned a /48 prefix that gives you 65,536 standard IPv6 /64 networks.
