Matt.
Stacking 700 frames should provide a very smooth image...even with the gain fully maxed.
Try using sliders 3, 4, and 5 for now. Everyone has different techniques for wavelets, but I've found sliders 1 and 2 introduce a fair bit of speckle if not used very carefully.
But that's just my opinion. I've read lots of people only use sliders 1 and 2. Each to their own, and it's a case of whatever works best for you in your processing routine
How about telling us your routine?