X5s sound interesting too, though they are new and priced at $249 from what I see.
Custom 3s have sunk price-wise, but seem to pose a fit/comfort issue for some. I am not a fan of over the ear style, so the X10s are a better fit for me.
Also, didn't see where epitheless says the X10s are dark. In fact, he told me he returned his X10s because he felt the highs were a bit much for his tastes, but I could be mistaken.
If the X10s are cousins to the Sleeks (close in sound, but more, deeper bass), then they sound like something I would like as much as I like the Sleeks. elnero, a Sleek/X10 owner, says he likes them both. Good enough for me, I guess. But I will find out for myself soon enough.