I too, think that the mix ratio is way off. I end up sometimes having the mix set on 0 or 1. You have a good work-around to this problem, but as you said, you are left with only the one delay engine
I'm a session musician, and have been using this delay for the past few months… generally happy with it… has some good sounds. I like being able to put a tempo in and then set two different delay note values. I have noticed some issues with tapping the tempo in however… quite unreliable.