25 minutes would be VERY fast for Central to the Hyatt. I was at the Hyatt two weeks ago. It took about 25 minutes to get to East TST. I went from Central to the Hyatt at 4:45 on Tuesday afternoon, which took about 40 minutes.
As for the hotel, it was great. The Regency Club breakfast includes eggs/omelette, bacon, and sausage. The Club staff were also quite helpful with directions to tourist attractions, including Google street maps. It was very nice to have an outdoor heated pool in November. Because it's mostly surrounded by hills, the outside looks different than downtown. The pool opens at sunrise, and I strongly recommend a morning swim.
I thought it was very good. Yes, there isn't turndown service, but I had a better overall experience than at Park Hyatt Milan. Plus the rate was about half of the other two Hyatts. But then again, I am a bus taker. I like sitting in the front row of the upper deck and getting city views.
One warning, though: At Checkout the hotel will offer to settle payment in USD or HKD. The USD rate has about a 4% markup.