I work in a SaaS company, and we run "a lot of Azure". We open around a dozen tickets annually. The response is a mixed bag. The response times are pretty good, but it depends what will you get as a response. Sometimes you get asked a bunch of irrelevant questions just to get a simple answer (which actually helps). Sometimes you just can't get them on the same page. There are support engineers that just do not know what are you talking about. Typical example: snapshots. It took me once like 10 emails to clarify that I'm having issues with managed disk snapshots, not with blob snapshots. At the end I'm not even sure he was still aware what am I asking, the guy was completely oblivious. He finally sent me some screenshot of his own control panel (where he sees much more info than the user does), to show me something, where I actually noticed something else that unstuck me. But if he didn't we would still be sending mails back and forward.