HR is also much newer facilities and decor wise but it is within the red light district of Nana. Unless you need the amenities, the Hyatt Place Sukhumvit 24 is quite nice as well and a short walk to the BTS. That would be my personal preference since it is in Phrom Phong which is an expat residential area with Emsphere & Emquartier malls and restaurants connected to the BTS station. In terms of distance from the airport, its Hyatt Place 24 < Hyatt Regency < Hyatt Place 1 < Park Hyatt < Grand Hyatt and the taxi should be somewhere between ~400THB for Place 24 to ~700 THB for Grand with highway toll.

I personally hate the Grand Hyatt because traffic is insane if you need to take a taxi and the nearby malls are a bit generic.