Yes, don't confuse ExxonMobil stars with AAA diamonds, not to mention Michelins rooftops (?) or whatever you'd call them.

Refer to the links in this thread (which I've bumped) to get to the valid ratings directories:
http://www.flyertalk.com/forum/showthread.php?t=131312

AAA smartly trademarked the diamonds, so others can't copy them. Stars are not protected, and as such, Expedia, Travelocity, Priceline, et. al., throw around stars with not nearly as much research and strict criteria. So don't put much weight on the rating unless it comes from a AAA, Mobil, or Michelin.

Getting to your question, the Hilton Harrisburg and Towers is indeed a current AAA four diamond. I'm sure AAA would like to hear about your experience there.

I haven't had any bad experiences worth noting at 4D properties. But I have been frustrated with AAA's three diamond rating.

It seems some full service hotels get 3D simply because they don't have the proper amenities to be 4D, even if they are offering top notch service.

Meanwhile, some limited service properties (Comfort Inn, Days Inn, etc.) land the 3D rating because they have top notch amenities for their class, but provide little service beyond what you'd expect at a motel.

In any case, I almost always try to find experiences posted here, on www.TripAdvisor.com, or other first hand knowledge. This has been extremely helpful.