This is my opinion, so take it for what it's worth. But I'll betcha everybody who's moved on from boxes to open frames like Timber and etc. will agree.
I don't care who the box comes from, what's inside the box, or how much electricity it gulps down at the plug. The useful area of coverage - the "footprint" - of a box drops off drastically as you move out from underneath the box. It might be as bright as the sun directly underneath, but things go downhill really fast outside the box.
The Duolux 600 is 22" X 22". That's bigger than a lot of boxes, but you're still looking at the basic physical limitations.
Duolux claims a 4' X 4' footprint in flower, and 6' X 6' in veg.
THAT IS NONSENSE. It's the same nonsense every one of these box builders claim to various degrees, so I'm not picking on Duolux exclusively. In the fine print, Duolux mentions hanging the light 24" above, and I imagine moving the light that far away helps the footprint a little bit. If the walls are reflective. I'm not willing to run a light that far off the plants and waste photons.
Compare that to an open frame with COBs. You suspend the open frame roughly 12" above the canopy, and you spread the COBs out to give more even coverage. If your COBs can slide on the rack you have the ability to scootch lights this way or that way, depending on the need. Better footprint, less electrical usage, less wasted photons.
Thermally, boxes make no sense. Stuff everything inside a metal enclosure, then add fans and vents to mitigate the fact that all the hot parts are cheek-to-jowl inside. Why not hang the driver and COBs out in the open where they can pick up on the slightest breeze?
Boxes are toast. People just don't see that yet.
