I had a fantastic stay at the SGS in April. One of the best...
If you are Plat this is the place to stay. Fantastic benefits. , and a great hotel.
However , getting to the Tourist spots like the grand palace etc was a nightmare. For that reason, you might be better of on the river where water taxis / boats are available.
It really is quite a hard call. The ROS is a bargin on points , and the SGS is a bargin in $.