This is pretty decent. I'd give it a 3.5 if I didn't have to round to a full lippie.
I have terrible purple undereye circles; really terrible. My "after" undereye circles with full makeup are pretty much equivalent to most people's "before." The fact that I have thin, almost chicken-like skin under my eyes and I am very fair (cool-toned NW15) doesn't help any. All concealers crease on me regardless of type of eye cream (or even not using an eye cream).
I started using correctors to help with my circles. This one is okay. It's about 1.5 shades lighter than the Armani corrector #2 (an orange which was just too dark for my skin) so I think it'd be fine for paler complexions.
The texture is very thick and firm. I initially tried putting it on like a regular concealer and it would not blend and looked horribly, horribly cake-y and thick. I switched my technique this instead: I press my ring finger into the jar, almost like I'm taking a finger print on an ink pad. I wind up with a super thin layer of the corrector on my finger, which I then press gently into my undereye. I repeat this for about 3 times per eye for extremely thin layers. That way it doesn't look cakey or thick at all.
It does crease a bit, though, despite these very thin layers. I set it with powder and it still creases. And it does not get rid of all of my circles; my circles are covered maybe 30%. I could keep adding more layers and get that to maybe 60% but it would just get so thick that it's not worth it. But at least my circles are alleviated by like 30%. Better than nothing. Then I cover them with concealer.
Overall, not a bad corrector, and light enough for paler complexions. It creases and needs to be put on carefully. Better than the Armani one in terms of color for me (although that texture is fantastic and it doesn't crease or look too thick).
Update June 2015: I started using this with the Sephora Pro Airbrush Concealer brush and WOW what a difference that brush makes. It applies this corrector much, much thinner so it sits better on my undereyes. It still creases a tiny bit, but much less -- and it looks so much better on my skin.