I haven’t stayed yet but I was there last week for a meeting and thought it was a strong property - indeed on the back of that me and the missus are booked in for a night early in November,. There’s no question that the Lume could certainly wear the Hyatt Regency branding I’m just entirely unconvinced that Hyatt’s name will attract more guests.
I definitely see where you’re coming from with IHG saturation in Manchester, but neither Hilton nor Marriott are so prevalent in the city and their Conrad or Westin brands could do with an outing north of the Watford Services gap! Of the two, I reckon Westins wellness type brand approach might work best.