Every year the LED bulbs on sale are replaced by a better design.
As incandescent bulbs age their beam becomes ever greyer. LEDs remain bright throughout their lifetime. Usually 50,000 hours.
Your first statement is true. Since most headlights today are halogen, this part of your answer needs some qualification. The halogen element (chlorine, fluorine, bromine, iodine, etc. are halogens) facilitates the redeposition of vaporized tungsten from the filament back onto the filament instead of the inside of the glass envelope in a standard incandescent lamp. This keeps halogen lamps burning more brightly as they age than standard incandescent lamps. LED's on the other hand, lose about 1 to 3% of their brightness per year (I'm not sure what hours the mfr's use here to denote a year) but they are not perfect...yet. LED's certainly outperform any incandescent/halogen lamp today, and unless you have an early failure, will probably last until you replace the bike with another. LED's currently emit between 90 and 100 lumens per watt. If a manufacturer's claims exceed those numbers significantly, they are probably inflating their claims like amplifier makers of old. More of anything sells better.
If your bike uses H4 lamps, go with the F2 LED. Read this
on the ST-owners website. The author is/was a lighting engineer and helped develop the LED H4 lamp. In fact, if you have the time and want the knowledge, search for Spiderman302 on that website and read all his posts. He is a pretty impressive guy.
For now, go to the link above (Read This) and choose page 17 - watch the video in post #331. While this guy is pushing his own brand - the V4 - it is still the F2 LED lamp that is currently the best out there, and beam patterns don't lie. What he is saying about each example is an education in and of itself.
If you buy it from Evitek (China). it usually takes 2 to 3 weeks to get to the recipient, it will probably be the cheapest price you will find, and as mentioned in those posts, the woman who takes the orders is Cindy. Her English is not perfect, but very good. I've bought two sets from them and have been v. happy with them - on my ST and V Strom.