Upper days or Push and pull days? Which is better?

[zxim]

I have push(chest shoulder triceps) pull days (back biceps), each one having only 4-5 exercises per day,

Then I have a short upper day consisting of 5 exercises
I have a longer upper body day which is about 6-8 exercises

But which one would lead to more growth for my upper body?
Push pull days (push & pull done twice a week)
Or upper body days? (Upper body days twice a week)