Probably the cost first. The Sandy Hook club has a lot of great features, and I've been on the fence about joining as it's an investment. Second, I like Barnegat Bay a lot, there are a number of interesting places to sail to. The Sandy Hook club area has a headland behind it, so getting back in may be tricky at times as it blocks the SE seabreeze. Shore Acres is open to the south.
SAYC suffered extensive damage from Hurricane Sandy and at present their amenities are limited but enthusiasm is high. They are in progress of funding a new building. I raced a regatta out of there last summer.
SHBCC is a very nice facility. Wide beach, showers/changing rooms, gazebo and lots of social functions, above all... a whole lot of catamarans!
I sail Raritan Bay, where SHBCC is located, all the time on another boat I race on regularly, which may also be why I like a change of scenery.
Sandy Hook does allow guest to sail out of their club a couple times, to try them out. After that you'd be expected to join. I have no idea if SAYC does the same. Both have websites.
'88 H18SE Arís