If you like to spend your evenings with a three course meal and a show, then no, you probably wouldn't have much time use it. If you're ok with grabbing a quick bite at O'Sheehan's or the buffet and spending an hour or two in the Thermal Suite, then yes, it will probably be of great value to you.
When I did my Epic cruise in the Med, I loved sitting on the Thermal Suite balcony as we left ports. The hydro pools and sauna were perfect for my sore legs after a day of walking.