I can't see how you can be good at one fighting series but hopeless at another, as they all have the same basic input techniques. Can you beat the bosses in KOF? I think a lot of people learnt to play fighters by playing SF2, and then just transferred those skills to every other fighter they played (Mortal Kombat & the SNK fighters).
Champion Edition was the first game to speed up the gameplay, but only by a little over World Warrior. That's why the game was known as Street Fighter II Dash in Japan- the "Dash" represented the extra speed.
With Turbo, the only real addition it had from the bootlegs was the speed. That made it more fun to play, but World Warrior and CE you could play more of a strategy game, more calculated. Capcom was going for gameplay balance, so they didn't add many new character moves. I prefer the Alpha series, as it has aerial fireballs, the gameplay has new features, and the speed is selectable.
