All the LED headlamp reviews I've seen start out great - and then get disappointing real quick, as their owners get some time to evaluate them - and replace them over and over.
While the theoretical lifespan of a LED may be longer than a HID bulb, the real-world lifespan on the current crop of LED headlamps
isn't.
Basically, the manufacturers either overdrive the LED to make it bright enough for the job, or can't figure out a way of moving heat away from the LED fast enough to keep it from cooking itself. Result: Lifespan measured in weeks, rather than years.
At some point - after they get the bugs worked out - they're going to be superb.
Right now, they're not worth the time, money and replacement hassles.