For a place that roasts their own beans, I would expect a little better.
Also, for a place in the Sunnyslope area, I'd expect lower prices.
That being said, Grinders is a good place to go if you live in the area and really don't feel like driving down to Roosevelt for a cup of coffee. It's certainly better than McDonald's coffee, and at least better than Starbucks as well.
But if you're really into the coffee scene, then no. I'd definitely not suggest Grinders as your first introduction to Phoenix coffee. If you really don't care very much and just want somewhere peaceful to go read a book, eat a pastry, drink some sweetened coffee, then have at it. Grinders is what you want.