I just recently tried this concealer - and WOW!!!! It's so impressive especially considering its low price. You can find it for about $5! It's super creamy and very pigmented so a little goes a long way. It blends nicely and can double as an eyeshadow primer (although not as effective as some proper eyeshadow primers).
Yes it will crease, but honestly what concealer doesn't? To prevent creasing make sure to set it with a powder and voila! If you find it to be too thick, try applying it with a wet sponge - it goes on like a dream and looks flawless. That, or mix it with a little bit of face moisturizer or eye cream and apply.
I honestly can't think of another concealer that I have liked more although I did just place an order for Eve Pearl's salmon concealer so I shall compare as soon as I receive it.
Tip: for very prominent dark under-eye circles, use an orange/peach based concealer as the orange tones will neutralize the blue.