I'm pretty sure there's no bot behind the eXch Support account, at least based on some of the various discussions here. Judging by this reaction, it seems @Synchronice got a reply to the PM here after 40 minutes, which can be considered relatively fast for a non-automated reply.
These replies didn't feel like a reply from a bot, nor from the AI, they were on point and felt written by a human.
In cases like this, I consider being considered as being a bot to be a good thing.
That's what I thought

By the way, regarding to Customer Support, I'd say that replies are very fast but the actual process of problem solving takes a long time to my mind because my issue still hasn't been solved (anyways, I'm okay with Exch, I'm not in a hurry).
One thing that I also liked about Exch is that the conversation goes through your order's page. There is no need to message them somewhere else, the CS team replies on to your order page.