I'm a week into my use of this range as a #BBRecruitReview-er and loving it so far. The major thing for me is moisture without oiliness as I do suffer some dry patches on my face, and a smoother texture on my skin overall.
As far as buying the products continuously, if you're unsure I would say go for the serum or the night cream first, those have been my favourite so far.

The serum is light without being drying, and you can use it day and night- I do! A little of it goes a long way too. I enjoy the slightly heavier feel of the night cream and I believe that's where most of the moisturising comes in.
I'm excited to see even more progress especially with my hyperpigmentation :)