I did a lot of research on LED bulbs in headlights and even tried some out in tests. Several things that make them complete failures for headlights designed for halogen.
1. Completely useless in melting snow from the headlight, even the best ones that are supposed to melt snow, but don't. Fog will also stick to the headlights and not evaporate off like it would with halogen.
2. Color temperature and color spectrum are very poor, forcing them to run much brighter to compensate. So a 10% gain in your perceived visibility while taking away +80% of oncoming traffic's visibility.
3. They are all 100% not road legal and no LED bulb for halogen lamps meets DOT standards. I would suspect any shop willing to put LED bulbs in might be breaking the law in some states?
Beam patterns are not as big an issue with newer, better LED bulbs, but still not ideal. Most LED bulbs are indeed plug and play, but might run into issues with daytime running light mode without modification.