The more I think about it, the less I'm disappointed with my marathon performance on Sunday. I ran every mile, with the exception of mile 25, within 45 seconds of my goal pace of 7:14/mile. As much as I hurt over the final 10K, my slowest mile was 8:25.
Until this one (not counting the trail marathons run), I've been knocking 10 minutes or more off my previous best times. Maybe those days are over and I need to be satisfied with incremental improvement from here on.
Either way, I haven't run the distance any faster and could have run it a lot slower Sunday.