There are a lot of factors that help us decide the right LED light we need but quality of those lights is equally important. No parameter in particular can decide the quality, it is always a combination of different features. Few links below can help us identify them.
Comparing efficiency of different light bulbs to identify their quality.
However cheap LED lights may become, the cost of quality products is still high.
Differentiating between the low quality and high quality LED lights is not that difficult, you just need to identify the differentiating factors.
Light color or the color rendering index also affect the quality of lights.