We stopped in while driving between Eugene and San Francisco, drawn by the "Pies" sign. Breakfast (garden omlette) was perfectly OK if not historically significant. Typical diner fare. The only standout comment I can make is that the servings are HUGE and two reasonable people can easily share a single order.
Prices were a tad on the high side, but given the portion size, that may be justified.
Now on to the all important PIE. I consider myself a cherry pie connoisseur, and give the Powderhorn cherry pie an A-. What I LOVED about the pie was that the filling was tart and genuinely juicy. It wasn't a homogenous pectin blob. The crust didn't quite live up to the filling, but was still well above average with good texture on top.
The staff was friendly and efficient. We'll stop in again the next time we're driving through Grants Pass. We just wish we didn't have to go across the street to get espresso.