I think the two fighters that personafy that style which is the most conventional style I've seen is Juan Manuel MArquez and Marco Antonio Barrera, it means you are the purely orthodox fighter who keeps his hands up, uses fundamentals in their purist form.

I think guys chronologically from Ali to Leonard through WHitaker to Roy JOnes and Floyd Mayweather have adapted their great athleticism into boxing which means, they have a wider stance, more upper body movement, hands held low and use the shoulder and reflexes to get away from punches. There will be a lot more guys in the next generation of both Brittain, US, and Cuba that have adopted this style. ALso places like Kazakhstan or wherever, you are seeing even the ex-soviet countries adopting a more fluid style of fighting.