Just changed mine out today...
Assumed that Car Max had changed them out before I bought it from them since it was sitting at 32k when I got her. Well, you know what they say about assuming. F*ckers had never been changed and I'm sitting at 67k miles as of the swap.
All of the gaps were right around .6 and I felt an immediate difference after changing them out. Gonna have to hit the wife's 4runner soon as I get a training holiday. Got hers from Car Max as well (different location) and the mileage was about the same when purchased.
Great write up. Helped me save a lot of (fiddle f*ckin') time.