Been reading up on the LED replacement bulb situation.
1) It seems that light manufacturers have finally gotten stuff right and modern LEDs do play well inside reflector housings. This is done by using a very narrow line of LEDs which closely mimic the dispersion pattern you might see from a filament.

Philips Ultinon H4 has its LEDs in a very narrow strip
2) Downside is instead of using many LEDs to produce a big amount of light, LED lamps designed to work in existing housings now use as little as three tiny LEDs. This means those LEDs are being driven very hard, which requires lots of current (often as much, if not more than halogens to begin with) resulting in very hot drivers which sometimes require active cooling. Most led kits that promise 200% output will do so at 70-80W, or about 150% at 50-60W (compared to a stock 55W halogen). That makes them uncompetitive with HID projectors (35W-50W) and somewhat in-line with new HIR bulbs from Philips (Racing Vision) and OSRAM (Nightbreaker Laser) which have 150% output @ the standard halogen 55W.