Ice cold IBC out of the bottle is Root Beer Nirvana.
If I'm traveling the Turner TP and stop at the halfway point convenience store west of Stroud, I'll get a 32-oz cup of soft ice and a bottle of IBC from the fridge section and be G2G. I despise the root beer they have on tap.
They have it at Pop's in Arcadia, and I have seen it at Food Pyramid in Tulsa once as well.
Short of that, I will drink IBC. But I really prefer IBC's Black Cherry to their root beer. I don't regularly drink soda at all, even diet, so I am very particular on how I will spend my carb allowance.
+1 when I was helping my friends on Saturdays deliver furniture for their store, we always made a stop at A&W for a frosted mug of root beer. Then Godfather's Pizza...