I have exactly the same issue as dsmbennett. I love the unit, but once again I found myself strugling with the very same volume drop issue last night and I spent approximately 6 hours trying to get the presets on approximately even level.
My problem as such is very simpple. I have two distorted rythm and lead sounds. One rythm and one lead with delay, etc. and one rythm and lead without them. The problem is that the dry sound is at least 2dB louder which is very well reconizable.
In other words, how to get the wet preset loud enough? I cannot lower the dry presets level, because there is this short lack in the the preset change during which the volume is momentarily much higher being very unusable.
By using dual mono routing I got the levels closer, but it is still not as good as I want it to be.