Through Hangout Dialer it works okay from what I gathered. The problem is if you use GV to dial out by default using the phone app, it always fails. The only workaround for now is if you force GV to ask you every time you dial out -- that works for some people but not me. I'm not sure about receiving calls; didn't test that. I've already reverted back to Marshmallow and probably never going to update my phone until they fix the problems, if ever. Other SIP app have different types of issues reported but I don't have first hand experience with them.
Good to know. Have you tried installing a third party dialer and setting it as a default to see if the problem is related only to the Huawei stock dialer?