Pros: It's close, not too expensive, and well run
Cons: it's a manmade hill next to a gravel pit with not much vertical
Mt. Holly is the best of a mediocre lot. It has the most vertical, the most area, the best snowmaking/grooming and the best maintained lifts of the four. (even a high-speed lift, highly unusual for such a small hill.) There's a nice beginner area and the blue runs are pretty tame so it's great for families or those just starting out. The black runs on the "backside" are mildly diverting for accomplished skiers.
I go to Holly several times a year and always enjoy myself. Of course, I adjust my expectations accordingly - it is a man-made hill with only about 300' of vertical after all. With the right attitude, it's a great place to ski.