Hoist vs stacker

Thanks Mike, wow that's quite a difference in heights, especially when rafters will be for storage of some sort. Thanks for explanation.
Because the bridge has to be high enough to not colide with the roof of a pickup or SUV. Where as the 4 posts have no bridge . Tops of 4 post columns are around 7-8’ where as tops of 2 posts are 11-12’ depending on brand , capacity and if it has extensions .