Portstewart has some otherwordly views and holes ...Castlerock is solid with lots of quality ......both are fine golf courses....as an infrequent visiotr to the Emerald Isles ....I with Huck in that some of teh holes on the front nine are so good that it pushes Portstewart forward.
I also thoroughly enjoyed the loopers at PS , I carried my own at Castlerock, which was fine...
I'd say that the quirkiness, more overt architecture of Portstewart won me over, .