I'm not sure "we're busy!" is a great response to concerned customers. Especially savvy concerned customers with social media. The capital WPE has received has moved them from #teamDavid to #teamGoliath, and that takes a certain amount of grace to pull off.

We left WP Engine several months ago, mostly because of cost, but I can confirm that support was less than stellar. Not consistently, we worked with some great, friendly people too, but there was more than one time when we received pretty terrible support, from folks who seemed to know a lot less than I do about WP (which isn't all that much.) Crappy support is kind of the norm everywhere, though. We got bit by an image that was hotlinked I didn't catch, it was viewed over 5m times, our WP Engine bill would have been over $4k in a month, had we not been in the three month money-back trial. (Which worked out great for us, I'm not throwing any shade there.)

We moved to Synthesis, the price is perfect and the site runs great, and while their customer support is quick, it's had its moments, as well. At the price we're paying, I'm willing to learn more about fixing the issues that come up myself. I almost don't want to say how happy we are with them too loudly, for fear they'll face the same growing pains as WPEngine if they get too popular.