My wife and I checked OHW out because of a Restaurants.com special (got the $10 off $20 food coupon for $1.50!) It's a bit far for us to go, but we've been there twice already.
The food reminds me of a place in CA that had equally great mesquite grilled burgers. The salad bar is good too. I just wish they had real bacon bits rather than the fake stuff. All of the other salad ingredients are fresh and delicious, if somewhat standard. The single serving plate is reasonably priced and generous in proportion. Too large, really, because I had to take my burger to go after eating the salad! It made a great dinner.
My wife enjoys the onion rings very much. I sneaked a bite of hers and can attest to their quality. She is not as jazzed about this place as I am, but does like the food.
Weekdays this place can be quite busy due to it's proximity to business. However, we did not have to wait in line to order, found an open booth, and our food was ready in no time. It's a burger place and has it's own special character (meaning old building and decor.) If you are looking for good burgers in Phoenix, this is the best I've found so far.