The folks that could afford the costs of the LED lamps swear by them and get upset the moment someone mentions there opinion of HID lighting being the better choice.
If you are deciding on what kind of lighting to use there are alot of things you should be taking into consideration and there are multiple choices that can work (HID,LED or flourescents). The cost of the fixtures, there efficiency as in lumens per watt, sufficent lumens per sqft, the color spectrum, amount of heat, bulb replacement cost, and an amount others are the things to consider.
HID Pros: the most efficient lumens per watt, long bulb life, yield. Cons: Heat is the big one requiring you to spend extra on ventilation/cooling, balasts/fixtures can be pricey for some getting started.
Flourscent Pros: Price of bulbs, Not much heat so can be closer to plants, buds grown with CFL's are considered by most as better quality. Cons: Not as much yield as an HID, Not as efficient as it either, lower bulb life.
I cant give you alot of info on the pros and cons of the LEDs because I havent used them. However there said to be more lumens per watt. The big con that I can think of is the cost as anyone I know of that has had any bit of success with LEDs all had the high end fixtures another con would be that LEDs will take longer to flower them than an HID.
here is a video that someone linked to me in live chat once.
http://www.youtube.com/watch?v=_CtROw3uiVg
Just have to think things out and decide whats most important to you and go for it there really isnt a wrong answer light choice wise. The answer is what you feel will work best for your budget and situtation.