The biggest problem I think is having bad connections to the drivers - LED lights need constant current / voltage, and bad connections will ensure they fail much faster than their rated lifespan.

I think by far the worst problem - and an extremely annoying and expensive one - is that LED lights are far less reliable than manufacturers' claims. The claim, of course, can be anything you like and cannot be verified.

This is particularly true when you get a bad batch.

When lights start to fail, getting replacement can be very tricky - businesses will happily sell them, but will not happily replace failed lights and make you jump through hoops.

The weak point about commercial LED lights is the drivers - they are very critical to the lifespan of the light, but often they are manufactured poorly.

Actually the real problem is not manufacturing but consumers.

Everyone wants the cheapest product, yet everyone knows that you get what you pay for!

So consumers buy the cheapest product, then complain that it is not premium grade.

People remember please: YOU GET WHAT YOU PAY FOR!

The worst thing I have encountered is unscrupulous competitors.

Manufacturers will spend huge amount of money in design, R&D, testing, refining etc.

But then a competitor will reverse engineer the product at almost no cost, and undercut the price, and on top of that their product will be junk. This creates a perception that the entire LED lighting industry produces garbage lights, and also decimates the companies that have put in the $ to create high end product.

Dimmers are also a problem. They are often very low quality so the customer thinks it is the light. 

The biggest problems with LED lighting:

- Low quality spectrum

- High failure rate

- Over-competition causing reduction in prices and hence quality

I think the biggest problem is that a lot of manufacturers from China (not all of them) create low quality commercial LED lights at insanely low prices. This drives out the good players, and brings everyone else down to also sell low quality cheap junk.