The first of all the smell, in my opinion, is amazing.
Secondly, after washing my hair with Redken Acidic Bonding line shampoo and using same line conditioner and leave-in treatment, I noticed my hair are softer, more manageable and less frizzy. I have mid-length long, 2c curly hair. My hair is very dry and frizzy, if i don't have any treatment. My hair feel much better using this line. I've been using it only for two weeks, so I don't know what would results be in the long term period. To be honest I think you can have same result with lower budget acidic treatment/products.
Also if you are sensitive to the sun, you need to take into consideration that AHA increases skin sensitivity to the sun and risk of sunburn.