Unlike incandescent (in some cases) and fluorescent (in many cases), you will hardly ever see "fading" with LEDs before failure. That's because the failure is generally in the driver circuit and not the LEDs themselves. The enemy of these circuits, like most electronics, is heat. In fact, some large LED lights even have fans to remove the heat. While incandescent bulbs generate far more heat, they are not as sensitive to heat - in fact the only part that "does" anything is the filament that heats up in order to produce light - if it doesn't heat up enough, no light! As a result, an enclosed fixture (which includes a recessed can or similar fixture that is only open in one direction) needs to be designed to dissipate enough heat from the base of the light, where the driver circuits reside, to prevent shortening the life of the light.
Combine that with a cheap/poorly designed driver circuit and you end up with a recipe for failure.
A few things to look for that will help if the problem is a good-enough fixture but poor design/poor quality lights:
- DLC certification This sets certain minimum standards and lights designed & manufactured to DLC specs should do well.
- A good manufacturer's warranty. In a quick search on 1000 Bulbs, I found quite a range in prices on GU5.3 LED lights, with the more expensive ones generally having much longer warranties. A warranty is not necessarily all that useful due to shipping costs and other factors, but a reputable manufacturer will build things that are unlikely to fail during the warranty period as every warranty replacement costs them money.
- Consider purchasing from a local store. The big stores (in the US that's Home Depot & Lowes) and many small stores that cater to the trade will have very good return policies - bring in the broken item (preferably with a receipt) during the warranty and they either refund your money or swap it for a new one.