Hi Josh,
Yes the 8.5 speed was obtained between VM's on different hosts. My hosts are connected to an HP Procurve E8206zl switch with 2 x 10 Gbps SFP+ modules installed. I've enabled jumbo frames on the switch, and set the vSwitch to an MTU of 9000. I'm using standard ports, no trunking (haven't been able to get that to work for some reason, and not sure I see the need for it). The VLAN I've been testing on is the 'untagged' VLAN on these ports (ie: the native vlan in HP speak).