I've been using this for a couple of weeks now, along with the eye balm and the moisturiser, and I really like it. I've seen a noticeable improvement in my skin. Fine lines around my eyes seem to be decreasing, and my skin just looks better - healthier and clearer and with a glow. I need less make-up, and what I do put on seems to stay put and need less touching up. In the last few days, my skin has looked good enough to go without any make-up, except concealer for my under eye circles.
I cannot comment on the serum separately from the moisturiser and eye balm, as I've been using them all together. I purchased them from QVC as a starter kit to try them out after reading the reviews here. But after the first use I knew I really liked them just based on the finish they gave, and the ease of applying make-up straight over them.
As other reviewers have said, the serum is quite creamy. I apply one and a half pumps each morning and evening over my face and neck, including around my eyes. My skin is quite dry and dehydrated, and so I do use eye cream and face cream over the top, but I imagine a lot of people wouldn't need to at night before going to bed.
I'm impressed that I can see a difference already after only two weeks, so I'm going to continue using just these products in isolation from the rest of my skin care and see what else improves.