I haven't had the pleasure of flying with them, but I do have experience with their employees. I worked at a hotel where their crews laid over. Air Jamaica crews are, without a doubt, the nicest, most sincere, lovely group of airline employees that I have ever encountered. Compared against the likes of other domestic carriers employees (starts with D, ends in A), who routinely humiliated the front desk, screamed and complained incessantly, they were a breath of fresh air.
Air Jamaicas planes are very new as well.