Starting from today all my sites have native IPv6 connectivity. As a matter of fact IPv6 addresses are there on my sites and services (mail, jabber, DNS) for a long time. But till today I had to use SIT tunnel at some places. Now Hetzner provides IPv6 subnet on its virtual machines. This allowed me to fully renounce the tunnels and get native IPv6 connectivity.
But it is not a time to switch off IPv4 yet, tunnel is still in use at my home.