KEY TAKEAWAY (if you wish to avoid reading the whole review) - try to ascertain before booking, or at reception, if your deluxe room or suite has connecting doors. (Connecting doors=noise leakage).
I have stayed at Hyatt Regency ca. 5 times, but this was my first experience at Hyatt House (the difference between the Regency and House being the latter is semi-self-catering). I had a mini-suite.
To my instant and initial alarm, I noticed my room had a connecting door to the adjacent suite. I had horrendous problems at the nearby Hilton in 2024 as ALL their suites have connecting doors and I had to change rooms twice.
Fortunately, no noise issues arose, but DOUBLE-CHECK IF YOUR ROOM/SUITE HAS CONNECTING DOORS. The pictures on the website are ambiguous - some deluxe rooms have/don't have. I do not know if all suites have connecting doors - this would be a bizarre design policy, but connecting doors mean significant noise leakage so it's a kind of 'Russian Roulette' as to whom you have as a fellow guest next door.
The suite was fine and comfortable. However, there were no cushions for the sofa or desk chair and I had to go to Marks & Spencer to buy two at £17.50 each.
Strangely, whilst Hyatt Regency rooms mean you usually have to pay for breakfast separately or as an add-on, in Hyatt House rooms it is included. This does make the House option somewhat more budget-friendly. The breakfast was fine and the service efficient.
Gym - fairly basic equipment but on top floor.