The sad thing is, the only card that would have fit my original case (a true two-slot card) was the PowerColor "Reaper," which was also a $599 card (and which would have actually cost me $599, as I was at Microcenter). I just overlooked it in the damn spec sheet as I was frantically trying to pick a card while standing in line with the employee handing out vouchers bearing down on me.

Don't get me wrong, the Gigabyte "Gaming OC" I ended up with has a longer warranty and a slightly higher clock speed (and probably a better cooler, since it's thicker), so it's certainly not bad. It's just that those aren't the specs that really mattered to me in retrospect. I'm still kicking myself about the cascade of upgrades it caused, and also that it's 2xDP/2xHDMI instead of 3xDP like the "Reaper" card, which means one of my three monitors behaves slightly differently than the other two. It's an annoying reminder of my mistake.