no not at all, i got the cards for less than $440 so doesn't bother at all, and my 2nd card is for free, at least for now. can't complain right now, and enjoying being able to test around.
also Titan X did better than my old 980Ti, single GPU vs. single GPU. as for the new 1070/1080 series, i am sure they are great but don't want to spend more than $400 per card, high end GPU and those Titan X's for less than $440 is a bargain, regardless of how you look at it. (2nd GPU, might get it from my buddy for about $320-350, he used professionally)