We normally sail Norwegian, and have also sailed Royal Caribbean a few times. Our reason for choosing Pullmantur for this trip was solely cost - the cruises with this line are often very competitively priced. We are a couple in our mid 30's from Scotland.
Our travel agent warned us that this is an old ship, that we're not paying much to travel with, and to set our expectations accordingly. We read through details of the ship and noted the key differences - that there is one main dining room, no choice of restaurants, and only a small selection of bars. We also noted that entertainment is in Spanish.
We both absolutely loved this cruise. It is one of the most relaxing cruises we've ever had - and we will definitely be booking Pullmantur again. However, this cruise will not be for everyone, and it's important to appreciate that this Pullmantur is different - not necessarily better or worse.