Yes, I have native IPv4 too, with the usual NAT. I think the default router that Comcast will rent to you actually is dualstack in this way too -- IPv4 NAT, and IPv6 prefix advertised for devices that want it.

I actually played with NAT64 for a bit (IPv6-only internally, all IPv4 space is mapped to a special /96 in IPv6-space and NAT'd at the router, and local DNS server on the router returns translated AAAA records for IPv4-only hosts), but dropped that when I simplified my router config. It works, it just takes a bit of config :-)