I have found that in my experience, no matter what the specifications of the host and the fact that we have 1GB network everywhere and good enough NAS. Export to OVF takes mega ages to complete. It always seems to go at a speed no faster than 6MB/s.
Is there a setting somewhere in vcenter to get this to move along at a faster clip, IE a speed that most modern cellphones can dwarf by all measures. Like a "business usable" switch to on attribute in a configuration file or GUI. It seems like a deliberate throttle, as there is no fundamental resource usage or limitation that I can see or am aware of that would slow this down to such a steadily rubbish speed.