We get 93 octane premium all over the place down in our part of the world. Thing is, when I'm travelling around the country (really around the North/NW), the octane is a bit less to the tune of the best you may get is 87 or 88...even had to use 86 a couple time. I've never noticed much of any kind of issues if I used the lesser octane rating. Mine wasn't tuned the last trip (but skunk ryders was) and he was getting great gas mileage with no adverse effect from the lesser octane we were using and neither was I.
Would I prefer to use a higher octane? Yep.
Will I run what's available and not worry about it? Yep on that one, too.