I've lived in the Prescott area for 8 years. Haven't been into J&G for probably 4 years - too many bad experiences.
Go to STG Firearms in Prescott Valley. It's where I do all of my business and the guys there know what they are talking about. Plus they have great prices, even matching Wal-Mart most of the time, and much better firearms, as well, such as SCARs and REPRs and all that other pretty stuff.
Want to get a firearm Cerakoted? Yeah, STG Firearms does that, too. I've had several done, as have some of my guys and a number of our students, and everyone has nothing but good things to say about them.
In my experience, pretty much every other gun store in the Prescott area has let me down in one way or another. Except Bucky O'Neils and Bill's Trading Post, they just don't always have what I need and are a long drive for me when STG is so close.
I've always liked J&G, however I don't frequent it because usually their prices are usually too high on what I'm after. On the other hand if you're looking for a Makarov, an SKS, a British Enfield, etc. or surplus ammo it's a great place to go....or at least it used to be.
I second all of Rizzo's recommendations:
Bill's has awesome personal service and a good selection. Same with Bucky's. And so far so good with STG...I really hope they succeed here as they have the nicest toys by far of any gun store in town! On top of all the top flight AR's and such, they carry classIII items in stock, and top of the line 1911's like Ed Brown, Wilson Combat, and Nighthawk..IN STOCK!