You might want to look at adding a CX430 or such to this - I had a (probably identical) Corsair 750W pulling 800W at the wall and it was just a little too much for it. It handled it OK, still ran all of my components without any issues, but the PSU got really warm and started making an audible 'click' every few seconds. Removing one of my cards from it's rails got it back to it's happy place.
You're probably just fine at 750W at the wall, especially if it's not getting too warm, but just forewarning you might be near it's limits.