I have had bad experience with a Samsung laptop. I purchased the machine new in 2012. A few years later I was unable to boot into the UEFI, the F2 and F4 keys wouldn't work anymore. I knew it wasn't the keys because I used a separate keyboard to test. Apparently, there was a known fault with pre 2013 UEFI firmware. Some customers were completely bricked. Samsung replaced motherboards free of charge. Fortunately, I have been able to manage OK but they'd sold me a faulty product.