My preface: I have type III/IV curls that I normally only wash and wear. I have not tried blow drying and flat ironing after using this system and probably won't do that, so I can't attest to how straight the hair looks and holds up after applying heat. My rating here is based only on how my hair looks after wash and wear.
It was with great anticipation that I hunted down and purchased this kit, which at this time is only available at select Target stores. Since the product claims to smooth frizz and the like, my hope was that I would be able to apply it and continue to wash and wear my hair, enjoying a frizz/pouf free style and get curl elongation. Immediately after completing the application I did two-strand twists on my hair, using Eco Styler Argan Gel, rolling each twist up about halfway on medium size perm rods. I covered my hair with a satin bonnet and slept this way. The next morning my twist out was really pretty. My curls were defined and somewhat loosened. I slept in my satin bonnet again that night, without doing any twists or using rods, and woke up the next day with somewhat of an afro, which is the way my hair would be in this situation without the use of this system. I wet my hair well in the shower and attempted a wash and go. It was ok, but I didn't think that it really looked any different than it did pre-system. My curls experienced the same amount of shrinkage as normal.
So... based on my experiences, and how I plan to handle my hair (continue to wash and wear), I don't think that it's advantageous for me to continue to invest in and use this hair system. If you plan to apply heat and wear your hair straight, then this may be a Godsend for you but since I haven't tried it that way I can't vouch. I continue to enjoy the Shea Moisture line overall.