1. No. of slots provided for GFX cards...SL / CF support.
2. Power Regulation and Capabilities
3. BIOS OC options
4. Component quality
5. No. of fan headers.
6. DDR speed support
7. No. of storage ports, USB ports
8. RAID support (also on business boards)
9. Higher quality sound support and more ports
10. Troubleshooting options, voltage metering points, etc