You need a static IP address for this to work is the downside, and depending on where you live and who your provider it it can be difficult and/or expensive.
I don't think ipv6 only is feasible yet unless your audience is exclusively in Asia where ipv6 uptake is much higher due to them running out of ipv4 years ago
They have poor reputations and are blocked from streaming sites and so on. But when you're the server, that doesn't affect you.
Note that you need a static v4 and DMZ because the tunnel protocol is a very simple one - presumably because they run it on giant routers. It just puts a v4 header in front of the v6 header. No TCP or UDP.