SO TGN's High Mountain Whites would also be nonsensical classification that sounds sexy, so they can justify a sexy price ?
Not sure if boar would be too abrasive in the long run is my main sticking point.
High Mountain White isn't a nonsensical classification, but it isn't an indicator of high quality either. It's an indication of two things:
1. The species of badger that the hair is taken from and;
2. The location on the badger itself that the hair was taken from.
HMW is taken from a very small patch on the neck of a Chinese badger. It's rare, so it has a high price. Because of the rarity and price, some people value it more highly than other grades. Is it better than silvertip or super? I don't know, because that depends on how it's treated, who makes it into a knot, etc. Because most manufacturers of brushes have their own sources for badger hair, it's hard to compare them. For example, Rooney Finest and Plisson High Mountain White probably come from the same species of badger, but they're not sourced or treated the same way, so how can they be compared?
It's the same with Manchurian, Super, Silvertip, etc. There is less of these hair grades on each individual badger, so they're more expensive and have that perception of 'exclusiveness'. Different manufacturers have different sources and production techniques too. That's why my Frank Shaving 'Manchurian' cost $20 from eBay, as opposed to a Simpson Manchurian which might cost $250-300. Are they even the same hair? I doubt it, but they probably come from the same species of badger. The best you should expect from grades of hair is a basic understanding of where it came from, and maybe some general characteristics of the hair type.
Omega boar is the same grade all the damn time, and it softens up pretty quick. You'd be unlucky to find it abrasive. Exfoliating but soft is a better way to describe it.