I am a yoga instructor and teach a dozen group classes/week as well as maintain my own yoga practice. I also play tennis, hike, swing dance, etc. so I'm very physical. Floating helps me release muscular and emotional tension.
There's this concept called "Pratyhara" in yoga, where one withdrawals their senses to move closer to a meditative state. The flotation tank is pitch dark, which calms my mind, and cuts out all sensory input and takes me there. I get to be fully with myself, it's a gift for myself. It takes courage to go deep within, and floating supports that.
I find when I do it more regularly, it helps relieve deep layers of stress I didn't even know were there. I find more peace within. There's a deeper letting go and a feeling of surrender when I float that I do not get anywhere else. I was a regular receiver of Watsu at Harbin Hot Springs, and find Zazen to be a safe, clean substitute. There's a healing atmosphere there and conscious community.