When I first moved to Pittsburgh I went on the hunt for a place to buy comic books, and so a location in Oakland was very convenient for me. I stopped in at Phantom after being recommended by other locals. They are located on Craig right in an easy place to walk if you are in Oakland; I suspect parking might be a little tricky, but easy for bus riders.
In regards to appearance and selection, this is a nice store. It is spacious and has a great selection, and there are a lot of things to choose from. It is very well-appointed and nice. Based on selection and appearance, I'd probably give 5 stars.
Ultimately, I did not become a regular customer here because of the customer service. In my first visit to the comic shop, the man behind the counter stared a hole through me as I browsed, never speaking, just leering at me with a stone face. When I said hello or smiled, a terse nod was the only response. On another visit I tried to join a comics conversation between employee and customer, and was basically rebuffed; maybe I should have minded my own business, but I'm used to being able to have chit chat with other fans in a comic shop. I'd give this about 1 star.
Overall, this is a nice store that doesn't give me the service I expect. If you have a good experience with the employees you'll probably love it, but that has not been my experience. I decided to shop elsewhere.