From IPv6.rs FAQs I get the impression that they only provide IPv6 route through their tunnel. I think self-hosting something only reachable via IPv6 would cause you trouble accessing it in IPv4 only networks - which are still far more prevalent than IPv6.

Hurricane Electric provides such IPv6 over IPv4 tunnel facility with /48 block routed to your network. I’ve just used this service for testing my IPv6 knowledge, so performance-wise I’m not sure how good it is. So, if IPv6.rs provides a significant performance over the HE-TunnelBroker, then I’d suggest you go with IPv6.rs given a decent price for the service.

If you are considering a simple to set-up tunnel utility for your self-hosting applications, I’d suggest you consider other tunneling options which have both IPv4 and IPv6 capabilities. Some widely used ones are Cloudflare Tunnel and Ngrok. You may also use Tailscale to connect both server and client via VPN. Using Cloudflare or Ngrok would involve some privacy concerns, as they can see the traffic passing through the tunnels in plain text.