My family and i have stayed at both agnes and 1770, its a trade off really, agnes has grass sites, you can walk to the main part of town, from memory the toilets and showers were very clean with good water pressure in the shower ( i live off rain water so i tend to live it up when i'm wasting someone elses water
) we've never had a promblem with management but have heard some stories of both good and bad. We did a drive through only last week and was a bit dissapointed to see they have scrapped the beach front sites in favour of cabins.
1770 on the other hand has more sandy sites, good playground / park if you've got kids, the closest pub is about a 10/15min walk away but the veiws are well worth it. Did a walk through here last week and noticed they've put in a little cafe next to reception although Kahunas pizzas are well worth the delivery fee.
Haven't stayed at the Capt Cook park yet but will be in Feb for the Blues and Roots Festival although when we booked our site the owners told us to bring heaps of mozzie spray so not to sure what to expect
Maybe book into a few days at each, i don't think you'll be dissapointed.