Hey Hockyfam. Fellow MA camper here also.
I frequent OOB also and usually stay at Hid n' Pines as it is within easy walking distance to the beach. I also live having a good size hardware store and supermarket within 1000 feet. Powder horn is just up the street and both campgrounds abut each other. I do believe the same family owns them both now. I find Hid n' pines to be a great family campground that is very laid back and enjoyable. Bathrooms are the cleanest I have ever seen. They clean them on the hour every hour. This year they just renovated a main bathroom building with all tile and Corian type counter tops. Absolutely beautiful. Never saw a campground renovate like that before. The staff is excellent and very friendly.
I will have to disagree with King Yankee. I do not find it crowded at all and I usually go around the fourth of July when OOB is considered the busiest.
Hid n' pines also has a very low number of seasonal sites so you are always surrounded by other vacationers and never feel you are in someone else's back yard.