What counts as 'good' in music is very subjective. It can vary by what culture you are in and what time in history. These days anything goes. I'd not heard that guy, but he has something different. There's a long history of people abusing various equipment.
I did use flat wound strings when I did a jazz course, but I am more used to round wound and traditional rock sounds.
Do whatever works for you!
!BEER
Especially in a time when we think we've already heard any combination possible, experimenting in the most strangest ways is required if you wanna stand out. Learning to do that in an artistic and successful way is the challenge