I used the 788 one just to clean the director's headphone when there is to many wirellesses. It is not usable on a mixtrack.
I use the 688's Dugan on a mix, on a talk show. I test it, and leave it on. 5 or 6 mics (4/5 handmics,1 headset, 1 stéréo mic) in noisy public places. It really helps me to provide a usable mix.