Okay, Rincon is a quiet beach, usually deserted, in the mouth of a small bay,with no hotels in site, no hassling vendors, no booths, no signs, no blaring radios. nice white sand and a fresh water lagoon to rinse off in.
I haven't been to HI and Cancun, so I have to apologize.
Lastly, it is far from Las Terrenas to Las Galeras/Rincon. You take a guagua for 50 or 100 pesos from Las Terrenas to Samana, in the morning this takes aorund 2 hours or less. From Samana market, you take another guagua for 30-50 pesos to Las Galeras. Then you take a boat or pay someone to drive you to Rincon.
I recommend that you paya bit more and let someone else deal with the hassle - if you PM me, I can give you a phone number for a trustworthy taxi driver out of Samana - who can pick you up in Las Terrenas and take you all the way to Rincon for lunch and beach and then back to your hotel in Las Terrenas.
I have done the guaguas when I had time, but they can be cramped and it all depends on how tired and cranky you are when you decompress on vacation.
For anyone with a few extra bucks, it is well worth it to pay a driver.
okay, so PM me if you want the taxi info. Enjoy!