No problems here with AT&T fiber. Yes, you do need their box (the bypass isn't even possible yet on their new model that they seem to be installing everywhere now). But the IP passthrough works well enough for me so that my router gets the public IP and I can connect to it using any service I've tried to host. I make the best of it by using their wifi (which on the BGW320 is pretty decent) for untrusted devices & iot stuff.
Oh, and I use DDNS, but I have never had the public IP change on me.