Adam,
My reference to SH vs NGLA was an attempt to frame the comparison in the context of two great, but different, golf courses. While golfers may have their preferences, on a once in a lifetime or daily usage basis, both are great courses where comparisons fall short, except in Wayne's eyes.
As to Ballyneal and Sebonack, both aren't conveniently located unless you live close by.
I think Sebonack benefits from the East End's summer influx of vacationers AND its neighbors. Golfers who come to play NGLA, SH, Maidstone, Atlantic, The Bridge, Friar's Head, Laurel Links, Southampton and Easthampton will give thought to playing other courses, Sebonack amongst them.
Hence, I think Sebonack will attract more attention and play.