Dell :: M6500 1600 Mhz And 1333 Mhz Memory

After reading the m6500 discussion thread it sounds like the consensus is that 1600 mhz memory makes no performance difference. But then a lot of folks seem to have configured their machines with 1600 memory and the below review suggests that the memory will help.

http://www.legitreviews.com/article/842/1/

So to have this fully hashed out, I think we need to answer the below questions:
1) If you order the extreme processor does the BIOS recognize the 1600 mhz memory?
2) Even if it does recognize it does it make a difference?
3) Why did people with the extreme processor order the 1600 mhz memory?
4) Can we fill in the WEI scores for memory using 4 and 8 GB of both 1333 and 1600 memory with the extreme processor?