I went over to my buddy's house last night to check out his new ASUS GTX 1070 STRIX. I will say, the card is pretty amazing. His ambient is around 21-22c, and his temps stabilized at 62c at full load. In silent mode, the card was boosting to 2036MHz and in OC mode it was boosting in the 2050MHz range. It didn't take much to get over 2100MHz while gaming. I'll have to go back over and do some stability testing later on.
He's gaming on a stock AMD 8350 on a 1080p montor and he's bottle-necked badly. GPU usage at 1080p was only hitting 55-65% In most games. I was showing him that he's in need of a new platform upgrade to support this card. We did fire up Overwatch @ 4K with DSR, and with EPIC settings we're getting a Solid 60 FPS. We also fired up the new Batman game with all of the Gameworks settings enabled at 4K in DSR and he was blown away. I must say I was too because the performance was really good with no AA 40-55 FPS. He hasn't owned a NVIDIA card in 10 years, so seeing batman with all of the goodies enabled was a new experience for him. He upgraded from a Radeon 380 4GB.
Anyway, all in all I think I'd grab a STRIX card if I was going with a 1070, the low temps alone I think warrant the purchase. Never mind the card was practically in-audible. I've never been a STRIX fan, but this card changes that for me, and I think ASUS nailed this design.