Clients of mine that have purchased in Perry County have been generally pleased with the school system. I encourage you to check the various specialized school report sites for specifics. While Perry County is no hotbed of drugs and crime, it seems to make its way into the papers every so often.
People attracted to Perry County value some space around them, and kind of share that "don't fence me in" sort of sentiment. While there are certainly still some good buys here, I see the pricing narrowing between Perry and the rest of the Harrisburg area. Since Shermans Dale is one of the most accesible to jobs areas of Perry County, I believe I see it even more here.
For Target/Costco/Starbucks/Barnes & Noble type shopping, you'll be doing a really easy trek to close by Mechanicsburg, Camp Hill or Harrisburg. But for a really decent hoagie on made-today bread, or a session at Curves, you can now do it all in Shermans Dale!
I'd be happy to answer any other questions you may have about the area.