Just before I checked out, I requested to see Deluxe(41sqm) and Grand Deluxe(51sqm).
The deluxe room twin is quite small as the St. Regis brand.
The grand Deluxe king is spacious with sofa.
You may be disappointed if you get just deluxe room.
The premier Grand Deluxe(where I stayed) is 46sqm so it is not as spacious as grand deluxe, but it has a nice view bathroom with separate shower.
If the size is important, you should choose Grand Deluxe(maybe only king bed).
If you need a comfortable bathroom, you should choose Premier Grand Deluxe(maybe two double beds only).
Unfortunately, I could not see the suite on that day.