This is just some sales guy (or store owner) in a Cambodian music store. No surprise that he's no virtuoso and doesn't really know how to get the best out of an arranger. He can't even pick the right backing for Black Magic Woman, by far the worst of the two performances.

What I'm choosing to get from this video are sounds of the tones coming from the MZ-X500. IMO the acoustic guitar wasn't bad (with slides, etc.), the drawbar organ was decent (I understand Casio has implemented C/V and an adjustable leakage amount - hope they finally did a dual-rotor Leslie effect). The electric guitar would be good if it was played right. This guy only managed that in a few short segments. I play acoustic (steel, classical) and electric (after a fashion) so my opinion on the guitar sounds isn't completely uninformed.