I'm guessing that it's best to get the 750W if you're doing a single card solution, and 850W if you're doing a 2xSLI setup?

Just installed mine (750) & it is excellent. Eco mode works fine & I haven't heard the fan cut in yet even when pushing the system.
Had a little stress putting it in as I elected to use the SATA cables I already had from my last PSU. Fitted fine but just wouldn't work. Changed to the ones supplied & all was OK. I had assumed that these were "Standard". Oh well, you live & learn.

I have a 850 G2. I love this power supply!

8IronBob
Just pulled the trigger on the 850W version (Newegg was only selling it for $10 more than the 750W at the time).  That along with a CM Storm Trooper case.  Seems like that should pair rather nicely.

Yes price difference is small, worth definitely...
both PSU are good but on 850G2 is much easier to connect dual GPU as TITAN Z, GTX690,... and to OC little.
Special today when lot of people choose i7-5820K and OC instead mainstream Intel Processors and 100W space less heat and less fan speed in PSU.
 

No more EVGA 850 G2 on EVGA USA site?! 
Maybe they will not get some time? Now is available only 850 GS and 750 G2 is still there.
If someone thought to buy that model maybe is time to hurry.
750/850 G2 have great reviews from customers and five star on Newegg with barely few complains.
Customers like and new series 850 GS by Seasonic.

That's new silent series. Made by Seasonic. Models are 850 GS Gold, 1050 GS Gold, 1000 PS Platinum.
You will recognize them with white corner on box and Eco Mode Switch is near connectors made as button. 
And PSU case is smaller, more cubic, ...
If you see button as on picture that's from Seasonic
 

Excellent thing is because EVGA success to deal with Seasonic for nice models and that didn't influence on price.
Price stay same as previous models, not higher. And it's good because they choose Seasonic not CWT or FSP example.

Just curious, Will this PSU support 3x SLI 970/980?

Yes, 850 G2 is more for 780/980 SLI, not 3 way SLI.
There are enough place for connection graphic cards, but it's planned on first place for two cards,
motherboards with 2x 8pin CPU and few SATA, Molex.
EVGA 1000 G2/P2 have natural connection planned for 3 way SLI.  
3x 8+8 pin, 3x 8+6 pin, 3x 6+6 pin. For every graphic card 2 VGA connectors.
For something else is possible to use Perif or single cable for 8+6 pin.
 

I have the 750G2,just got it in the mail today as a matter of fact, I was wondering if someone could tell how to use the test plug that comes with it. I'm still waiting for the memory to arrive so I haven't been able to turn on the system yet and I want to make sure the liquid cooler I have works. 

Thank you.

I don't know from my perspective 750G2 and 850 G2 are little better than 1000 G2 and 1300 G2.
Because Eco Switch and different fan profile give more silence.
But if someone need 1000-1300W and want silence maybe is better to chose 1000 P2 and 1200 P2.

thebaddie
Hey there,
 
I just want to share with you this recently italian review of the 850 G2, it got a 94% score
 

 
HI, welcome, this your first post and new members are unable to post links before 50 posts.
You could send me on pp and I will post or you can post with space between and I will repair.
 

http://www.hwarena.it/2015/06/evga-supernova-850-g2/
 
Before some time I had idea too for building site with reviews of EVGA hardware for Balkan and East Europe.
But something like that is not possible because financial situation of people in that region. 
I had excellent idea, because Serbian language understand and talk people in 4-5 countries, they call different but that same as American English and English in UK.
And we didn't have big distributor for EVGA hardware to become sponsor, to pay sending hardware back, because someone need to pay and translation of every review on English and that need to do professional translator who finish school with certification higher level from English Language.
Germany or Switzerland, Norway, France, Italy are excellent countries for something like that.
But professional review, if someone do example power supply review should contact some national university in own country with proper equipment. 
Pictures made by professional Canon camera or photo. For that you need big distributor of some brand as sponsor and Balkan is not place for that.
When ASUS sell 3-5 R5E boards maybe and you need to call 10 days before to deliver in shop that what to talk further.

i dont understand the difference between EVGA SuperNOVA 850 G2 220-G2-0850-XR and  EVGA SuperNOVA 850 G2  220-G2-0850-X2? Better component on XR?