Not sure if something happened in transit, but my Rumblex Plus rattles loudly. It's a solid machine, weighing nearly 40 lbs. I look forward to using it.
I'm glad I went with the Rumblex Plus 4D. Having that added vibration feature (via a 3rd motor) greatly increases this device's versatility. My wife and I have been using it for a few days now, and we are both feeling a difference.