Just received my EVGA SC Reference card today (from somewhere other than OcUK) and so far I'm pleased with it.
I was debating about whether to go for the reference model or an aftermarket version before preordering, and after hearing people say how noisy the reference card is I was considering sending it straight back.
Thankfully, while it is certainly louder than my previous DCUII 770, it isn't really audible at all over my other case fans and is essentially silent at idle. I have my computer under my desk about half a meter or so away from where I'm sat.
I'm running a Bitfenix Spectre Pro 200mm fan as intake and a stock corsair case fan as an exhaust, both at minimum speeds, and while I wouldn't say they're quiet fans, they're not unreasonably loud either. The fact that my reference card isn't heard above them is great.
As for performance, I've only run a few benchmarks so far but the card out benched my 770 (unsurprisingly!) at 1440p max settings on Unigine Valley by 97% and on Unigine Heaven by 122%.
Not had a chance to test many games yet, but I've been sitting on Witcher 3 since the 19th of May dying to play it, so I'm gonna go and test that out now.
As for power draw / heat / clock speeds:
My card was boosting to 1339Mhz out of the box according to GPU-Z, a nice improvement over the rated 1190Mhz boost clock.
The fan speed hit a maximum of 56% (2436 RPM) and the maximum GPU temp was 85 degrees, but for the most part it sat at a stable 84 degrees (as it is designed to, I would imagine?)
Power draw was being reported as 101.2% of TDP, presumably because of the factory overclock applied by EVGA.