Also AFAIK bittrex uses Microsoft platform to power their engine - that makes scalability really painful, so I assume they are struggling with common problem in IT - How to lower the load, without lowering profits. As usual users will be those who pay 
With their problems on user verification and lack of support I expect them soon downgrade to the levels of Yobit or worse, so the scalability issue is almost fixed.
I know, I am mean, but they are also mean with their customers.