I got the spyder glass-lens housings, installed torchbeam (40,000 lumen 6000k) led in them. After proper adjustment, nobody flashes me, and I can see extremely well. I did the 4hi mod, but I never use hi beam. The darkest rainy nights are no challenge for this setup!
I have no problem with led bulbs in halogen housings... IF they are properly adjusted.
I will give room for those housings thst just splatter light everywhere. You simply can NOT adjust them to a safe place with led bulbs.
The spyder housings (at least the ones I have) do create a definite cutoff line. My brother put led in stock housings, there was much less definition for cutoff.
This is my experience, your mileage may vary.