I changed all my incandescent light bulbs in my house by LED's about 4 years ago. My savings monthly are about 30%. The LEDs definitely don't last the thousands of hours they claim to last.
The amount of faulty LEDs I've had to change in the last 4 years are only a little bit less than faulty incandescent bulbs in the same time period.
So in my experience, LED's are much more expensive, but 1/3 better in terms of savings per month, which is good, but not the exaggerated stats they give us.
For the amount of money I spent on replacing inexpensive Incandescents by LEDs, I figure I will only start benefiting after about 2 years or so.
What I also notice is that many of the LEDs I bought start getting weaker with time. Could be related with the brand that I bought, but not sure.