My BG runs better on premium (91/93) than on regular (87). The engine sounds smoother and IIRC, I had better power at low rpms. But it also dropped my mileage, by about 3 mpg.
In the end, I switched back to regular. I'm not racing or doing anything that requires maximum performance out of my wagon, it's just my daily driver. And if I can achieve the performance I want with 87, 87's what I'll stick with.