After using the Osaki OP-4D Ultima for a few weeks, I am thoroughly impressed. The 4D massage mechanism is advanced, providing a variety of massage strokes that mimic professional techniques. The body scanning technology ensures that the massage hits all the right spots, tailored to my body's needs. I particularly enjoy the zero-gravity position which enhances the massage experience. The touch screen controller is user-friendly and intuitive. Although it's a significant investment, for those who need regular massage therapy, this chair is a wonderful option. Just be aware, it's quite large and heavy, so plan your space accordingly.