I Opted for the 3-way.
I find it more versatile. You can slacken the three axis to give you total free or you can damp some of the axis for controlled panning or fix the horizontal axis for panoramics.
The drawback is the weight but that that really only comes in to it when you are carrying it.
A ball will give you total any direction type movement or you can lock it once you have framed the subject, but as soon as you release it, it goes anywhere it wants.
Heavier it may be, but I will sick with the 3-way.