I would say pay the 30 dollars for one checked suitcase for the comfort of having enough stuff with you. Honestly collecting bagsfrom baggage claim in JA was never an issue for me and in 15 trips never a bag lost. I am always so excited to be there that I could care less about a short wait. That said, I know you travel from SF--so maybe added hassle when changing planes on the way back? I would rather have a few pair of shoes (one nice pair of sandals, one pair of sneakers or water shoes, and one pair of flip flops) and enough stuff to get by with minimal clothes washing. True you can wash and hang things--but thicker items don't dry well in humidity and/or rain. I have done it both ways and after a couple of times with just carry on--switched to checked bag. I take my snorkel gear as a carry on and my lap top as my personal item--so checked bag was necessary.