With the SAN in mind, I'd base it on budget. If budget's tight I'd probably go with RAID 5. With a more open budget I'd *want* (but maybe not need) RAID 10. There are good arguments both ways, but your bottleneck could easily be your SAN itself. If by any chance you're running that V3700 on iSCSI (1Gb OR 10Gb), consider upgrading.
In the end both RAID levels are just as viable if implemented correctly in the correct situations.