Base camp to Katahdin, close in to Millinocket. Went with a diverse group of campers with hammock, tent and cabin sleeping preferences and everybody found their spot.
Pros are: clean (like super clean) showers and bath house, fire pit and picnic table at each site and cabin, super helpful, friendly hosts and last minute gear avail at the office (we got a waterproof map for Katahdin Woods and Waters National Monument).
Only con I can think of is the tent sites are a bit close together and barely deep enough to park a car (not sure if a larger SUV or F350 would even fit) - just a bit of a congested layout overall.
Would go back, nice option to the Baxter or other backcountry sites with no bathrooms, or for times those sites are all taken.