We just completed a stay at this hotel and all I can say is that it's quite spectacular. The huge lobby is gorgeous, with wonderful art work. The staff was unbelievable. We walked out of the elevator from the garage to check-in and an agent came from behind the desk and met us half way and greeted us, introduced himself and brought us over to the desk where he checked us in. We've stayed in Four Seasons and Mandarin Oriental and no one has ever done that.

Likewise in the Regency Club, the concierge and assistant each came over and introduced themselves and asked if they could be of any assistance, They went out of their way to locate a restaurant whose name and address I had misplaced. However, this was the only club I have been in where there was no hot appetizers, but the canapes were wonderful.

The room was average Hyatt size. As requested they gave us a non-connecting room with a great view of the Rockies (view rooms are even numbered). Quiet and nicely decorated. Self parking was very easy with no long walks.

This was one of the best Hyatt's I have ever visited.

Recently I stayed at the Convention Center Hyatt Regency for a conference. While there I contracted stomach flu and was desperately ill. The staff was fabulous, sending crackers and ginger ale to my room at 3am and even giving me extra time before check out the next morning. Even before the stomach bug, the staff had proved themselves with little touches, but the care and attention in this worst of scenarios made all the difference.

Excellent service by all support staff. I want to especially compliment the bell staff. They went out of their way to help me and were extremely respectful. All staff who answered questions on the phone or at any of the desks, including the fitness center, responded to me by name or asked how they might help me.

I asked for a room on a upper level and they made sure I had a view of the mountains. I was there for a conference.

Did not use the hotel eatery or bar since I wanted to venture out to the 16th St. Pedestrian Mall (I was somewhat disappointed in lack of variety and had trouble finding place to eat breakfast). But did go to the Sante Fe Ave. area and was immensely pleased with the art shops and galleries (an up and coming area some of the locals are just now discovering too), the clerks and staff at one of the restaurants and Chicano Center for the Arts near the Museum de la Americas were helpful and courteous You must go! Take a bus or taxi to get there.
We did have trouble with getting prompt taxi service from that district back to hotel however. The bus was actually faster and cheaper.

Denver has friendly locals and I'm sure you will find it appealing.

I was traveling on business and I booked the Hyatt Regency based on it's walking distance to my work site and other points of interest. I was impressed with my 4 night stay although I don't know how I would judge if I had to pay out of my own pocket. I gave it a 5 out of 5 because I felt like it was better than above average 4 out of 5. I think tripadvisor should adopt a 10 point scale. Anyway...
I booked a standard room with a queen size bed. Apparently, there was this big event going on that made the hotel want to organize the rooms so that the parties involved could be close to one another. That meant solo travelers like me got bumped. But when that happens, hotels upgrade you and that's what they did. I ended up with a room that was 1500 sq. feet. Definitely larger than any suite that I've been in. The guy behind the counter explained my options and was good at assuring me this was a good thing. And he was right. I had room service with their restaurant Altitudes, that was nice. Their bar was ok but the view of Denver was a sight to see. My room also had an amazing view of downtown from the 25th floor. Room was clean and the front desk answers the phone in a micro second. One time an entire ring tone went by before someone answered. I joked with them that they took to long and that they were slipping :))
But I really liked my experience here. Some say the price to park was to high but I have to disagree. Hyatt Regency is a top tier hotel in a major market downtown next to their largest convention center. I don't think $20 is to much to ask, besides, in the parking garage, they give you more than ample space for your vehicle's doors to open and to load/unload your items without touching the car next to you. And there are other affordable parking options around the building in public lots not affiliated with the hotel so it shouldn't be an issue. All in all, a solid choice for the mile high city!