I bought my first ever Raspbery Pi this week (arrived yesterday). Love it but was disappointed that no matter what I did I got dropped frames from HD videos when played with VLC. I installed KODI and same thing. Tried various tweaks, tried playing back from SD Card, USB hard drive and via wired ethernet to my NAS. Nothing would work properly.
I then saw mention of LibraELEC. Installed it and it works perfectly so far. Well done guys. Great job and I'm sure it will get better with each update.