Z15CAM, If he already had a custom water cooling loop in the build your advice your advice makes sense and cents(😉). However, it sounds like Mike is new and not going to be building a custom water loop anytime soon. That is why I suggested the Sapphire R9 290 Tri-X.
I'm not an expert in custom water cooling but have played around with it a lot in the last year or so (XSPC Bay res. XSPC Twin D5 bay res, GTX 670 and 680 water blocks, EVGA GTX 780 Classified Hydro Cooper block, XSPC EX360 and RX 360 rads AND MO RA3-420 rad) so I know this "obsession" called custom water cooling costs some serious $$. No doubt that custom water cooling a reference 290 is the best route IF you custom water cool and want the Hawaii chip. However, Mike just sounds like someone seeking the "best" video card between a R9 290/290X vs GTX780 he can afford. That's why I suggested the Sapphire R9 290 Tri-X.