I went with the flow. Typically, in the budget I had, AMD offered more computing power for the money. My most recent PC uses Intel. I just had to try the huge overclocking ability. In the end though, I used the same criterion.
I'm not the kind of person that sticks to a brand. I'm after the value.
As for the competition thing, I'm not too sure it isn't better to have an underdog, rather than 2 similarly sized companies, who could at some point see that they can just shake hands and agree to screw the customers together.