The only barrier for me to go IPv6-only is those VPS that are provided with a single /128 IPv6, and I do not know of a service that would offer IPv6 tunneling other than HE, that requires an IPv4 endpoint. The day I get a full /48 or /64 with my VPSes, I'm ready to drop IPv4.
Does your VPS assign you multiple ipv4 addresses? Otherwise seems like feature parity.
I use ipv6 everywhere, but I get annoyed when some features are missing.
For example, OVH won't let me transfer an IPv6 prefix like they do for IPv4. I thought I could just migrate my VMs to another box, but one of them had lots of clients with their own DNS/domains, so it was a huge pain to update.