I previously used the smaller Royal Red Light "300" panel for a couple of years, and recently upgraded to the 1500X model.
It's a massive improvement! There's definitely an additive benefit—the more of your body's surface area gets exposed to the red and near-infrared light, the stronger the overall effects seem to be.
After just 10 minutes in front of the 1500X, I feel energized and unstoppable, like I've got superhuman strength. My sleep has noticeably improved, and I just feel better in general—more vitality overall.
I held off on sharing my thoughts until I'd used it consistently for over a month, and honestly, the benefits keep building the more I incorporate it into my routine. Highly recommend the upgrade if you're ready for full-body coverage!