AoA is definitely an enthusiast's store. Eric and Tim are both very involved in the the Pittsburgh area fish club, and Tim is a key member of the plant club. Doug (another worker at AoA) is another member of the the plant club here in Pittsburgh, they are both very knowledgeable with regards to plants. AoA is the only place I know of in the Pittsburgh area that carries freshwater nerites for planted tanks. They always have cherries and often have other types of dwarf shrimp.
The inside scoop is they are also planning in the near future to have high-tech setups to sell more of the rarer plants. If you're a plant geek in the Pittsburgh area you should definitely check them out! Let them know about your interests and they're more than happy to talk "shop" with you.