After using this signature duo for a week, this is my review and opinion of the shampoo:

The packaging is extremely luxurious and I'd say is quite a statement and reflects what the brand is about!
The consistency is thick but not too thick, and because of this yoy don't need too much shampoo on your hands for an indulgent wash. It gets foamy with the least amount of product - in essence, a little bit goes a long way!
I have seen that my hair is shining, fresh and it leaves a sense of thickness (which is amazing because I have five hairs LOL)
The smell of the product is sensational. After one wash, you're guaranteed a smell in your hair for the next couple of days as well as a few compliments ;)
I'd describe it as a bergamot scent mixed with a tangy lemon scent; it's beautiful.
The wash itself i would describe as luxury! It deep cleanses without drying ones hair out (which is great for me as I am a victim of DRY hair due to bleaching and over processing); it detangles and protects at the same time.

However, with all this luxury comes a price to pay. The price of the shampoo is quite on the heavier side of the pocket but like I said, a little goes a long way so it will last quite a bit for the price you're going to pay!

In a nutshell, I would highly recommend this shampoo from the duo because it gives all the nice things it promises BUT due to a tight student budget, I would not unfortunately repurchase it again at this stage. :( (one day when I'm rich and famous, for sure!)