It's been a long time since I worked for Hyatt, but I stayed with them for 8 years largely for the comp night benefit. From what's stated here, it sounds like it's the same as it used to be. I used to get the full 12 nights as a part-timer. In fact, I sometimes got more, because I worked in the rooms division, and the rooms exec would sometimes arrange for a room outside of HR, and it wouldn't count against my allotment. One additional restriction: you used to not be able to book more than 3 nights at any one Hyatt. Also, it was all based on availability, so sometimes you'd request a comp stay and it would come back denied. The Grand Hyatt New York was particularly bad about this. They wouldn't accept ANY employee comps during the week, only on the weekend. I was told by their reservations manager that they accepted any and all employee comps on the weekend, and nothing in the week. Having said all that, I was usually able to get what I wanted.

Employee rates were set by the hotel as well, and were usually WAY less. That was how I was able to book New York: by getting employee rate during the week.

However, when I left ages ago, they were already in the middle of a long slide towards denying more and more benefits to part-timers. And there were some differences between hotels, as I recall. You'd really just have to ask the prospective employer. (And if HR is as pathetic as it was in my day, don't expect to get an accurate answer. Those people were idiots.)