Macbook Ram Speed Question (1033 or 1333 MHZ)
Depends on what you plan on doing with the machine but 9.99 times out of 10 you're better off going with more ram (8gb in this case), especially for RAM-intensive applications such as databases, virtual machines, music/video/audio/photo editing.
You won't be able to notice the difference. I would take 8GB of 1033 over 4GB of 1333 any day and twice on Sunday.