I am still sweating but think the fresh air kept me more energized.
The only drawback was the JS370 is much smaller.
However, its firm mat did enable balancing with less effort.
Maybe next time, I will place the JS550 in front of the laptop.
Trust your own Mind and Body and listen to both. The benefits of exercise and music have kept me moving. Being a Big Believer in the Benefits of Bouncing to MUsic on a rebounder or sitting on a stability ball, I have been adding music to most workout video files when removing the moves I prefer not to do. Check the links for my POMBarb Channel on DailyMotion and WellVideo.net and my.mail.ru