I have had success with retention (not growth-I'm too cynical (or realistic) to believe a product can grow my hair) using mainly one line: Oyin Handmade. I've noticed that their products keep my hair soft and moisturized like no other (which leads to a reduction in breakage, protected ends, and all those goodies that go into retaining my hair growth).
I did the exact same thing with Oyin, and I had the best results of any line I've used. I've never used Motions Moisture Plus, but I highly recommend their Lavish Conditioning Shampoo
My cousin-who has the thickest head of natural hair I've ever seen on a person-uses their hair lotion, and her hair stays soft and moisturized.