I haven't been at the Hyatt in Bali, but I have been to Bali.

I wouldn't stay at the Hyatt, but not because of the reason you're asking about. Bali is fun, interesting, exciting even, but the key is the local culture and the big international hotels sort of pull you away from the local culture. Further they ain't exactly centrally located. Ubud is much more of a fun place to stay. while you can certainly get there and back from the Hyatt, part of the fun is walking around the local area there. I stayed a few days in kuta, a few in ubud, a few in lovina , etc. If you want to stay at one of the Hyatts when you arrive, that's fine, but I'd definately plan to spend a few nights around Ubud there are some nice hotels and one of the world's finest there) and while the beach in Lovina isn't quite as pretty, I also liked staying there for a day or two.

Finally, two weeks in Bali may be a little much. I was there 8 days, and felt I could have used another day or two, but unless you dive, surf or can really lay back, once you get past 10 days, you may be pushing it