Although my own personal experience may not square with others, here's my take -
I had retrofits done on one of my other vehicles several years ago, at considerable cost. Aftermarket replacements were not available, so retrofits were my only option. I hired a professional retrofitter to do the work, and utilized only new, high-quality parts. I wanted them to look as though they came from the factory, with better performance than the OEM halogen reflector headlights (which should not have been difficult).
I will say that the company hired to perform the work did an excellent job; they looked as if they were OEM. Performance was a disappointment. Sure, they had that nice cutoff line, but I never thought that the area illuminated up the road was anything to gush about. Illumination to the side was quite disappointing. And something did not jive with the wiring - the only time I tried using my high beams (the retrofits were done only on the low-beam), my dashboard lit up like a Christmas tree. Newer cars have much more advanced and complicated electrical systems.
I'll never do it again. I will pay close attention to IIHS headlight ratings, just as I do safety ratings when it comes time to purchase my next car.