Not really. They are very ambiguous. On the one hand they say it is the default server that is used. Yes, they do say it is for testing. But it doesn’t say it is ONLY for testing.
Of course, I understand it is in their interest not to promote it too much and to promote their new cloud based services. But it is also in their interest to keep it running.
I would run my own one if I could find an easy PHP implementation. But so far I haven’t seen one that is bug free. And I’m only using it for Nat punch through which I don’t think puts a huge strain on the system.
(No I’m not talking about Unity 5.1 Networking, I’m talking about Unity 4 Networking)
Unity Technologies also has a fully deployed Master Server available for testing purposes…
Nowhere does it say after this which you can use to host your own games, the fact the word only is missing is making a huge assumption that it is for use for release use when it doesn’t mention that anywhere.
If you want to use it, then do, but it has no SLA and goes down regularly for long periods of time, basically if it does down on a weekend, you are waiting for Monday until someone reboots it. And yes this is only with reference to legacy ie 4.x networking.
It’s not for anything except testing. Don’t use it for your own finished games. It doesn’t matter what argument or justification you invent about it, the fact remains it will bite you in the arse.
In future I’d expect unity will come out with a proper paid service, but this is only my guess and only for UNet.
Server source is here, the old system uses TCP IP so as long as you can open a socket in PHP, you could create your own punchthrough using the source from here as a guide.