I recently bought the new Sephora X base coat, top coat, and two polishes. I was very anxious to try them as I've heard various things about the formula already.
The X line is supposed to provide a gel-like shine and wear with very good opacity. I immediately thought, "Well, I'll be the judge of that!"
This mani is a coat of the X base, two very easy coats of Deranged, and a coat of the X top coat. While Deranged looks a lot like Orly Galaxy Girl, I feel pretty confident saying that they are not dupes.
Deranged has more of a pinky-red to blue flash that is very apparent and duo cool while Galaxy Girl has a more prominent turquoise flash. There is also more of a purple feel to Deranged and more of a burgundy feel to Galaxy Girl. I'm going to go out on a limb, not having compared them side to side, and say that Deranged is more complex and awesome.
So, how's the wear, you ask? It's pretty great so far! I'm on the end of day four right now and I have a tiny chip on the corner of my right index finger. I also have some tip wear, but it's not very apparent. Overall, so far, I am impressed. Also, the top coat dried reasonably quick. I was terribly worried that my mani would take an eternity to dry without using quick dry top coat. I painted these four layers without waiting (or hardly) in between, sprayed everything with quick dry spray, then waited about 25 minutes. Then I got ready for my day! They were dry enough to function easily.
As far as I know, this new polish line is available on sephora.com and in very few select stores (should be in all stores around next summer).