My first D54250WYKH couldn't even get through the OS install. It had IO errors that were unrecoverable every time. The second NUC would consistently take a Kubuntu install but has intermittent kernel panics and reboots for seemingly no reason. And it near bricks using any kind of suspend mode in Linux - everyone is having that problem. You have to disassemble the whole NUC and pull the CMOS battery to get it to boot after any sort of suspend. Suspend is pretty important because these small cases use small, loud fans. Just a modern desktop, an idling modern desktop, is enough load on the GPU to throttle up the fan to full RPM.
I posted about my troubles on the NUC forums, along with many others. Intel says they don't officially support Linux so it's on you to fix. That's interesting because they sell the NUC with no OS. If it's intended to be windows only they should sell it with windows. Also in the firmware notes they talk about fixing a bug that was effecting Openelec, so obviously Linux is part of their testing.