Great Resort
You will have a great time. We loved this resort!!!! We ate mostly at the resort which was not bad. Enjoyed the Italian buffet and also enjoyed the two theme night shows with dinner buffet at the resort. The only restaurant that I recall was Linda Vista and we went early and got a table right up front with the most spectacular views of Acapulco bay. I have also heard that the restaurant and views at Las Brisas is highly recommended but we didn't try it.
We did the cliff diver show and it was very nice but didn't bother going the second time we were in Acapulco. My wife wanted to go to Taxco for silver shopping and touring but we never got around to doing the tour since it was all day trip where they picked you up around 7:00AM and you don't get back till around 7 or 8:00PM.
Many people who went to Taxco did tell us they really enjoyed the trip and enjoyed the shopping for silver items so you may want to look into it.
Have a great time and weather should be in the mid to high 80's every day at least that's what it was when we were there the same week in January last year. I wrote a TUG review for that trip at the Grand as well as our previous trip at the the Mayan Palace. I think you should get a lot of good information from all of the reviews.