Yes it is gated with armed guards at the gates. The hotel is nicer than most other hotels in Santo Domingo. However, it is not nicer than most other Marriott Properties. To give you a point of reference, it is nicer then the Ilikai Renaissance and St. Thomas Renaissance, buth of which are no longer flagged as Marriott properties. Avoid staying in the out building as my boss was originally assigned a room there once and said it was not very nice so he upgraded to the main buidling. The Executive lounge was nice and the rooms on the Executive floor were too. It is better than the hotel Grand Lina and El Embajador Hotel the other two hotel I have stayed at in Santo Domingo.
I have not stayed at the IC as I found the Renaissance Jaragua acceptable, especially by Dom Rep standards.