I love the Marriott on Grand Cayman. I have found this hotel to have amazing staff. They are friendly and helpful and I feel genuinely care about the guest experience.
The hotel is right on 7mile beach so it is easy to walk down the street or the beach to other hotels and restaurants. There is a place called "Coconut Joe's" right across the street which has decent and inexpensive food and drinks. I'm a platinum and have free internet, but I learned from another guest that there is a nearby coffee shop with free wifi. There are also many other things within a close walk (restaurants, liquor store, gas station for water/soda/juice etc).
The pool is small (the pool at the Westin is far nicer, but the staff doesn't even come close), but the Marriott has invested in putting "Reef Balls" in front of the hotel to promote reef growth and fish. It definitely makes for some more interesting snorkeling right in front of the hotel. There are also floating chairs/tables in the water as well which are covered. It definitely has a very "resort" feeling.
There is also a 'red sail sports' at the hotel for renting snorkeling gear, jet ski's etc, they also provide scuba services, but any of the local dive companies will pick you up at the hotel.
If you want to go to the RC for dinner, it's a decent walk or a really quick, cheap "bus" ride there (though be warned the buses stop early so you may want to cab it back). It's also just over a mile to walk into Georgetown for shopping, staring at cruise passengers, etc (or again, you can take a cheap "bus" or a cab).
There's also a spa on site (which I have never used), and a gift shop.
Overall, it really the staff here that endears this property to me. Time and time again they were friendly, helpful and really seem to enjoy their guests.