Mine worked out well for me, I see idle temps at room temp (20-25C) and max OC temp of 45C (on a GTX980 at 1440Mhz). Are you mounting the pump before putting the rad in the case or after? I found that I got bad temps unless I mounted the pump first (otherwise it wouldn't lay perfectly flat) then installed the rad in the case. Are you sure the pump is working correctly? I had a pump die on me and it did the same thing, I got it replaced and I'm now getting great temps.
http://imgur.com/a/gmXTW