I like the look. I think it's suitable for the highest levels of formality if worn correctly with all the niceties. I'm thinking about getting a nehru jacket and getting it cut down for the kilt. I absolutely dislike Prince Charlie coatees. And doublets are a little pricey for me. I don't think that you need the metal buttons for it to be formal in Highland attire, although it is certainly more traditional to do so. But those can always be adjusted to ones taste.
I am a traditionalist of sorts, but I prefer the spirit of tradition over the cookie-cutter image of "Prince Charlies only" for semi-formal/formal wear. So new modern or "vogue" types of jackets are fine with me... but let's not kid ourselves, in 20 years we may look back at them like we look at powder-blue tuxedos from the 70's.