You guys, the protein in SM products isn't hydrolyzed, and isn't even the hardening kind of protein--silk proteins are for smoothing and softening... It's all those rich emollients (butters and oils) that won't rinse off that's giving dryness issues. Every single product has shea butter in it, even the shampoo. Using each one back to back as your main source of conditioning and not using actual hydrating products in between will give that effect. It's no different than using grease or old school heavy dimethicones.
Try using just one product from the line and combine it with hydrating (mostly water/humectants) products and it'll do it's job and benefit your hair.