We've just returned from a lovely 3 night stay at the Hyatt. The hotel's in a great location, close to the shops, restaurants and good public transport links.
Our room was spacious, clean, and even though it overlooked a busy road there was no traffic noise. I'd highly recommend getting access to the Regency Club lounge. Breakfast provided there was fresh and varied, and the canape and cocktail hour is a nice touch. The lounge does get busy and there can be a little wait to be seated, but the staff are polite and attentive (and deserve a medal for their patience when dealing with some of the more 'challenging' guests we witnessed there during our stay!)