We are going to CSS for our first time ever in Jamaica. We plan to visit the falls and hang out at the beach. Since we don't want to bring every pair of shoes we own, we're debating which is better, keen sandals or aqua sock type shoes?
Either one of those will be fine. You won't need them while you're on the beach at CSS, but you will need them to climb the falls. If it were me, I'd probably bring the Keens for the falls, but the aqua socks will save space in the luggage.
On our first trip last year we only brought our Crocs and managed just fine climbing Dunn's River falls. I did get pebbles in my shoes and had to dump them out, which was annoying, and kind of wished I had aqua socks. However, they were perfect for the beach, snorkeling, etc. You can rent the aqua socks from the bus on the way to the falls for only a few dollars if you prefer to have the best of both worlds. My attempt to keep the # of shoes in my luggage always fails :-)