Based on the videos, I will probably stick with SSR.
A few years ago, we tried the GF Spa while the Disney Institute was being converted to SSR. (We had gone to the spa several times while it was the Disney Institute).
To me the GR Spa was grungy, and the hot tub rooms were small. It looks like they took care of the grungy, but hot tub rooms are still small.
When we go to a spa at a resort for a massage, we like to make it a half day event. I.E. arrive early, use the hot tubs and saunas, get the massage treatment, and the use the hot tubs and saunas again.
SSR is more spacious.