Slicing Up Your Routine

Simple question: What is the difference between splitting your routine by presses and pulls-or by the plane you are working in?

Example: 1) Day A-all the presses you do, Day B- all the pulls you do....OR.... 2) Day A-vertical presses and pulls, Day B-horizontal presses and pulls. What are the differences?

It seems to me that you could really dig into the body on the first plan. But, can it have adverse affects on the opposite days? With the first plan you would have to take more rest time between sets, the second you can overlap a bit... Also, with the second it seems easier to maintain balance.

Thoughts and opinions?

Be Complete

Just to be clear, I am just curious about what takes place physiologically. But I think I have found the answer. A fat guy at work told me that it is just a good mix up for variety- change it up some for adaptive purposes. Also, it can allow more rest between muscle groups. I have noticed that the WODs are whole days of pressing or pulling sometimes. I personally gravitate towards working in a certain plane- ie: chin-ups paired with HSPU or FL rows with planched dips. Maybe I will throw myself a curve ball eventually.