Those numbers seem pretty incredible for any panels. I can't imagine seeing >400W/panel that is rated at 200W. Well, unless you were driving around on the sunny side of the moon with massive cooling. Purely from a light source perspective.No formal testing, but I've finally gotten a chance to really put the 2x200W panels I got from them to work. The highest I've seen is 849W, though that was probably ideal conditions (cool summer day at high altitude, driving around the mountains so probably at least briefly got near-ideal tilt)
Highest full-day output so far was 5340Wh and 3500-4000KWh seems to be fairly typical with some clouds here and there.
They also survived a small hailstorm and a lot of highway driving without issues.