Politically, the ideas of Anarcho-Capitalism and Anarcho-Collectivism share some of the same traits. Even given that fact that we both oppose the state, there are still strong differences between -- philosophically as well as ideologically.
First, I am opposed to authority, wherever it may appear in society. I oppose it politically and legally, where one seeks to impose their "enlightening will" on others around them, using violence and coercion. But I also oppose it economically.
If your boss reduces your hours, uses dangerous machinery, or cuts your wages, they are practicing their authority against you. Yes, you do have the freedom to leave, and to take on another boss as the authority against you economically. You also have the liberty to starve -- to go out, quietly, painfully, and alone, as your way of resisting this miserable system.
In this, I find the perfect analogy of the state -- or, more deeply, the concept of a social authority. Yes, you can quit the state, whenever you'd like, but then you're under the immediate obligation of finding another state to become your ruler. And if this is too much for you, you have other liberties as well -- you can reject your government, its laws, its violence, and end up in prison or the gallows.
Yes, there is a liberty in Capitalism and the State. To the Capitalist, I can change my master (to an equally oppressive master), or to the state, I can change and move to another country. But no matter how often I move, I find the same thing -- the Dutch, French, African, and Korean governments are all the same! Likewise, I found that the Capitalist is as greedy, violent, and oppressive in Nepal as they are in Argentina.
And there is always the freedom to withdraw. You can avoid enforcement of the law, but you need to be in a prison! Oh, and you can also avoid the exploitation of a Capitalist system, but you need to be starving in the streets!
So, either way, to put a bullet in a man's head, or to deny him the right to work for bread, either way -- you kill the human being in the process. Stalin's "wheat confiscation" in the Ukraine is responsible to nearly ten million deaths, but I can't say that it accomplished anything different than the militarist aggression used in Poland, Czech, Afghanistan, and Korea.
I'm Anarcho-Syndicalist because of this fundamental reason: authority, whether it is born in a government or a capitalist, is a menace to human happiness and liberty.