Got a sample of this and while it's ok, it has TWO (count them - TWO) ingredients in it. Cyclopentasiloxane and Dimethicone Crosspolymer, both are types of silicones. So if you don't like a silicone feel to your primer, avoid this at all costs. I rather like them, and they don't bother my skin, but $42 for this is outrageously expensive. If I could find it say for half that, I might spring for it, but even then it would be revoltingly over priced.
Long story short - this is just silicone in a fancy-pants bottle and with a gaggingly high price tag. If you're good with that, then you will be happy with this. At least it isn't scented to high heaven like all the rest of Lancome's products! that's a positive for it. :)