I stayed at the Hamaca a few months ago. It was fabulous, much better than in the past, which was also darn good. The place has come a long way in 8-10 years and has really expanded. This is one of the few hotels that can compete with the best of Punta Cana. The grounds are huge and the place is classy.
Rats? I believe it. Any hotel, restaurant, or home can have them. I killed one as we at a 5-star restaurant at the Marriott in Cable Beach, Bahamas. It was on my girlfriend's lap. I told her "don't move, swatted it to the ground and stomped it". They comp'ed all 10 of us our meals. One of the guests owns one of Cleveland's finer restaurants commented, "All restaurants get rats on occassion, just like they get flies".
I stayed for a month at the Radisson in Flint, MI, 5th floor. I saw a mouse. It was in my grocery bag of munchies. I caught it and called security, who just carried it off. I complained and they did nothing but supply me a glue trap. I bought "real" mouse traps the next day, caught 5 in about 3 hours while I was out to eat, took pictures, wrote an article and threatened to publish it in local papers, and ended up getting my month's stay for free (I moved out that day too).
Having rats doesn't make it dirty, it means it needs rat control. All my homes have had mice or rats on occassion, perhaps not inside, but on the grounds. Rodents are part of our environment like mosquitos and squirrels. I hope the hotel is taking efforts to get rid of them because they multiply fast. They ususally keep out of sight and only go where the food is.
Hotels that have room service end up with food hanging out in the rooms, the hallways, in trash containers, etc. This will attract rats and cockroaches. The better properties are exterminated regularly.