1) The exotic WM was in Masters of the Wild, not Sword and Fist.
2) What flavour? The exotic WM has no flavour to speak of. It's just a way of accumulating more powerups with nothing except "must use something other than a sharp stick" to hold it together.
In general, there appear to be two main ways of representing skill with a particular weapon. You can use feats and feat chains, or you can use a prestige class. In S&F, you could see the latter option in use, with PrCs like the lasher and master of chains. CW and 3.5E seem to be taking the opposite direction. Instead of custom weapon master PrCs, there are various weapon- and style-specific feats, and a catch-all "exotic weapon master" class that really is just a way of getting more feats.
Both of these approaches have their good and bad points. A well-designed PrC gives a character an identity that feats can't really emulate; a lot of people like being able to write "master of chains" or "blademaster" or whatever on their character sheet. However, thinking up cool abilities to fill out 10 levels of advancement can be hard, and you don't always want to use up half your levels on one PrC. Conversely, feats are flexible and usually don't require as much effort to design; the downside is that without a class framework drawing it all together, they can be relatively impersonal.
The exotic weapon master achieves the unique double of combining the cumbersome mechanics of a prestige class, with the blandness and impersonal nature of feats. That takes skill.