So far, I've been running 87 because it doesn't have ethanol (or as much anyway) as the higher octane we get here in the Cornbelt. I may try the ethanol blend, but in my other vehicles it has resulted in poorer mileage.
The first two fills have been from Walmart (Murphy Oil Co.). I got 17.3 and 17.4 mpg, which seems to be pretty good for winter blend from what I have read hear and on other forums. In the past, I have gotten better results with Casey's, so I'll try that in the near future.
I'll probably run some Seafoam through my truck too. It has 24k miles, so that might not hurt anything. My truck is stock, so I haven't had any issues with the 87 octane.