Has anyone had good or bad experiences with Dr. Dennis Gross MD Skincare? I'm particularly interested in the HydraPure Vitamin C Brightening Serum, the HydraPure Intense Moisture Cream, the HydrPure Firming Serum, and the HydrPure Firming Eye Cream, but I'm also interested in comments about any of the other products in the line you've tried. Thanks!