Recently stayed at the Hyatt Union Square NYC for six nights and was overall quite happy with it. Located right at Union Square and close to the Flatiron district, the hotel location is the greatest plus - convenience stores such as Walgreen's are just steps away and there are all kinds of great restaurants within walking distance. Maison Kaiser, an all-day breakfast and pastries eatery, is just a block away. There's a Starbucks about two blocks away and an all-day Chinese dim-sum restaurant, Tim Ho Wan just half a block away. Reputable restaurants such as Gramercy Tavern, East 15th and the Union Square Cafe are all within walking distance.
The hotel's restaurant The Bowery Club did not have good breakfast (limited menu and bad coffee) but the Cobb Salad during dinner time was very good and reasonably priced. The hotel bar is actually quite beautiful and exotic during quiet times, but for most evenings, the bar was extremely noisy particularly during weeknights. The bar does not take reservations and good luck with finding a table. Drinks were good but very expensive!
At about USD$400 per night, the room was good value for money for a Manhattan Hotel. There's free Premium Wi-Fi (maybe because I'm a World of Hyatt member) everywhere for up to three devices anywhere in the hotel. I also had 2 free bottles of Evian water every day. I opted for the King-Bed room facing the Courtyard and the backs of other nearby buildings because the hotel is located near a fire station and I wanted to be free from sirens of fire trucks. The room was small but quite well equipped with sufficient closet space and drawers even with a big hotel umbrella inside the closet. The bathroom shower offered good water pressure but the water often overflowed beyond the shower stall if the door was not closed tightly. I particularly liked the edgy bathrobe with a hood - very nicely designed and hip! The King bed was comfortable but I missed my mini-fridge where I could have put my purchased fruits from Walgreen's. There was no doorman and no washroom in the lobby but front desk staff were always helpful and friendly.
My only complaint was that housekeeping staff, though conscientious, did not speak English well enough to understand my specific needs. The hotel also needs to change the duvets as I've discovered a blood stain on mine one night. A renovation might also be timely as my room looked quite tired and overall lighting was too dark.
Hyatt has recently changed its policy that making local calls from the room is no longer free. I never received any email about this policy change from the World of Hyatt and when I called reception, they told me it's still free. When I checked my bill prior to check-out, all my calls were charged $1 each plus telecommunications tax. When I complained that reception had told me a different story and they immediately apologized and took all those charges away from my bill.
Location location location was the biggest attribute of this hotel. Overall I was quite happy with my stay and would definitely consider going back on my next trip.