One of the worst Hilton Experiences Ever
I had a horrible Hilton experience 20 years ago and avoided the chain for 15 years- several years ago was "forced" to stay at a Hilton with work and had a great experience- have had wonderful experiences (am now a Silver member) until this past weekend. The Hilton at Union Square is one of the worst out there!
I had spent 2 weeks this past month directly across the street at the Parc55 Wyndham, and while it was not quite as "pretty"- the service was impecable-- the Hilton could take many lessons in customer service from their neighbors and it might do wonders for their guests!
RUDE! RUDE! RUDE! is what I have to say abou the staff here! Besides the fact that if you have ADA needs, this is not the hotel for you (no handicap accessible rooms with 2 beds available- because it seems handicapped people must not ever travel with their children)- long, long walks from the street to elevators, no restaurant deliveries allowed, no room service menus available in the room so unless you log in and try to find them on the website and no phone orders taken over the phone- so if you have mobility issues- walk to the restaurant or don't eat.
Hotel shuttle pick up to the airport is only available at one exit- not the main exit- so again we had to walk excessively after "finding out the hard way".... also asked to speak to the general manager, not available, and took 3 desk staff over 5 minutes to even give me his name, and I never did receive his phone number as I asked. 
The security guard on the last day was polite, the gift shop clerk was polite, one waitress was polite other than that I witnessed rude bartenders, rude hostess in the restaurant, rude desk clerks, rude curb attendents, rude telephone assistants, rude pool attendants (no clean pool towels either)-- it was so shocking and so disappointing after several wonderful years with Hilton all over the country. 
My family spends lots of time each year in hotels- looks like Carlson will be winning back some time from us again-- Hilton Union Square you BLEW IT big time! -If you are staying in the area, I recommend the Parc55 right across the street!