To sum it up: "WAAAAH! I BOUGHT A GAME IN BETA AND IT CHANGED!"
Bought it in Alpha, it changed a ton, loved it further. Suddenly, sprinting is added, and I'm totally just turned away by it. I still love Minecraft, I love what they're doing with the game, but something they did has altered my view on the game. When the full one is released, I'll be all over that.
Now, Menen and plad, forget off.