A question about patching, PAL users please answer

[Revenged]

I have a PAL unit and I recently burned my first game (US version of Crazy Taxi), and it worked just by using an Utopia boot cd. So does this mean all US versions of games work on my DC WITHOUT patching (with an Utopia cd, that is) ? If they do, is there any reason I should patch my isos? If it's all about the "borders" on TV, I don't really care.