If that PSU was having issues, it's a lemon. I think Phil was running on 120V back then too. 240V is easier on the PSUs, I hope you'll be using 240V with 6 S7s?
EVGA says you can pull 1300W DC from them, IE ~1450W at the wall for 10 years. That's good enough for me! Worse case they replace the PSU for free.
That's good to know as i was getting nervous after reading what Phil had to say. Looking at graphs, efficiency is decreasing at least 5% at or above 90% load.
Yes, I was running at 110/120V, but I sent them all out to hosting with sidehack- posted my review in Hosting service thread.
TL;DR: I like his arrangements and service.