You realize that the lumens rating on those lights is theoretical, right? In reality they probably put out half that. They rate them at the theoretical maximum light output as stated by the manufacturer of the LED emitter, assuming that you get the best of the best, top bin select LEDs from the batch and drive them with a perfect driver circuit with a large, efficient heat sink. This is never the case.

However, I do agree that those lights are the way to go these days. I can't think of a good reason to spend double or more for a name brand light. My current lights are a 5 year old MagicShine still running strong and a 1 year old, $35 "1600 lumen" ebay light with an Action LED lens on the front. They're both all I want in a light. I can run them on medium pretty much any time and be perfectly happy.