I haven't used Facetheory before but have been looking to switch to cruelty free products, and have been searching for a good vitamin c serum for a while. I ordered Regena C20. It arrived promptly and well packaged, which is always a good start. Have been using it now just a few days so too early to comment on exactly how it pans out, but so far so good. I was dubious when I opened it and it's quite white and gloopy. I'm used to transparent serum. However, I'm aware that's to do with the stabilised vitamin c, which helps with longevity of the product. The smell is a little frying pan oil 'ish' at first. So I had a moment of 'oh'. However, I'm also aware that smell is due to the high level of vitamin c in the product - which is a good thing. Assuming I've got my info right on my two 'howevers', that's good enough for me. And, when you put it on, it feels quite nice, it still slides, others have described it as sticky but I don't feel it is. It's just a little thicker. It goes on clear, it sinks in, the smell goes, and voila. It feels nice on my skin and works beneath moisturiser, sunscreen, make up, on it's own if you're just at home, all just fine - so I am feeling positive and looking forward to seeing how this product pans out for me! So far, I would certainly recommend.