I went with a four.
The quick response times, even for some of the bizarre errors I am having. The GMs and the GSs are very helpful and respond exactly when needed. The service is great!
Not a five because that implies perfection, and if it was actually running smoothly I would not be getting errors and problems.
But Aeria is one of the better providers I have had the pleasure of gaming with, I plan to stick around a long time.