LED lights are extremely efficient. They use approximately 85% less electricity than incandescent bulbs and as much as 50% less than fluorescents. 

The problem with the old fashioned incandescent bulbs is that they converted a lot of energy into heat instead of light.

LEDs however are quite cool - ie they do not convert huge amount of energy to heat - and so are much more efficient.

LEDs are not only efficient in energy usage, but they also last 5 to 50 times longer than other lights (30,000 to 100,000 hours lifespan).

That is correct. LEDs last vastly longer than other lights. Incandescent globes only last an average of 1000 to 5000 hours, CFLs 8000 to 10000 hours, and fluorescent globes 20,000 to 50,000 hours.

The reason LEDs last so long is that they are extremely durable: no glass components, no filaments, their lights comes only from excited semiconductor materials. The only issue is that they do cost more.

They do cost more but because of their low power use, they save you money quite quickly - and also, they require very low maintenance.

The cost of LEDs are gong right down, so even the cost issue will go away very soon.

One issue with LEDs is that their light is very directional. 

This can be a huge advantage eg with cabinet lighting and spotlights, but a disavantage eg with globes and table lamps.

New LEDs are getting around this problem by using diffuser lenses and relectors.