PE2800 Raid - Dynamic or Basic?

Good Day!

I have looked at the forum for this information, and I don't feel that I'm understanding fully. I have a 2800 with Hardware Raid 1 & Raid 5, and am loading SBS onto the RAID 1. Now Windows is asking me if I want to turn that Raid 5 portion into a "Dynamic Disk". Should I leave it as a basic or change to dynamic?

What is the Dell recommeded and why?