Relevant server setup is a SuperMicro X10SRi-F with the VM store via iSCSI LUN (not internal disks). I'm running desktop VMs (among others), so I have an nVidia Quadro 6000 + ESXi 5.5, the latest that supports vSGA, as I can't afford GRID and video needs are lightweight. At the moment there arent any shared devices I can think of apart from the video card, and at most a couple of passthrough devices, but perhaps I'm not aware of all the devices used.
SuperMicro's BIOS has a wide range of features, including SR-IOV (clearly virtualisation related) and ASPM.
I can look up what SR-IOV and ASPM (which it seems to depend on?) are, but it's at a sort of 'dictionary definition' level and I'm having difficulty figuring out their implications, which would help me to decide whether or not it's beneficial for, and I should, enable them for my scenario.