I usually use VMware Converter to migrate VMs from Hyper-V plattform to VMware plattform and that's never a problem when there's a short distance.
From a VMware plattform to another VMware plattform I usually using SRM and thats neither never a problem even over really long distance. A very short downtime as well.
But now I have customer for which I'm going to migrate, only 15 VMs, from Hyper-V to VMware and the distance are 500km. Sure, Converter will work but it will take some time to do it.
It's between different datacenter suppliers therefore connecting SAN will not work.
Well, this require existing VMM management server that has the VMM console installed. And this is also with a total downtime.
Converter is a better solution than this but it cant be the best.