Light bars are illegal for on the road.
There are a lot of leds that are very bright.
Diode dynamics are good but very pricey.
There are a lot of other brands that have good light output and quality for a fraction of the price.
AUXITO is a very good led brand and there’s about a million others.
I’ve found across brands as long as the leds are positioned on the sides of the unit they have an identical cutoff and beam pattern to the stock halogens
That's the issue, precisely. Cheap vendors advertize BS light output values. A headlight shoud NOT exceed 2-3000 lumens, never, ever. You'dre driving on public roads with other drivers facing you A LED source should not be "very bright", it should be better than OEM halonges while respecting the DOT or ECE framework. Especially in North America, with our prehistorical DOT regulations, forcing headlamps to actually
have glare (as opposed to ECE), and without mandatory headlamp washers for HID/LED headlamps (as opposed to Europe).
The second problem is the placement of the LED emissive surface. It's not enough for them to be placed on the sides - it's free-space optical engineering. 1 mm of an offset at the focal point leads to signficant beam geometry changes, different cutoffs, and different stray beam patterns.
There's a reason DD charges an arm, a leg and an appendage for their products. I'm not advocating for them specifically, just giving then as an example whereby in a product development cost, prices goes exponentially as you narrow down fabrication tolerances and MTFBs. You could have identical Amazon LEDs with a +/- 1 mm more of manufacturing tolerances, heat dissipation tolerances, or a much wider statistical lifetime variance, and the price will drop by half.. beause they're effectively crap.