Here's where I'm going to get shot for saying this but:
By the time you'd buy an XL710 you could get a 10GbE proper switch:
Gnodal GS4008 40 10GbE 8 40GBE Ethernet Switch SFP QSFP Cisco Nexus | eBay
$2200 OBO with more ports and 40Gig E too
By the time you'd buy an XL710 you could get a 10GbE proper switch:
Gnodal GS4008 40 10GbE 8 40GBE Ethernet Switch SFP QSFP Cisco Nexus | eBay
$2200 OBO with more ports and 40Gig E too