I've frequented this store for many years and have always had good luck getting help from the employees. Generally if I can't find a book, all I need to do is ask at customer service and they'll either point me in the right direction or help me to place an order for the book. The store has a good selection of product besides books as well including comics, games, collectibles, etc.
I've never noticed the cleanliness issues that some of the other Yelpers have mentioned about this store. Perhaps I've only shopped there on the days they cleaned?