Again...I don't know what to tell you. Your experience differs from both of my existing KVM environments at the present moment.

ESXi is not and has never been free, so I guess your one fear has already come to pass? VMware Workstation does have a sort of "starter" hypervisor for free, but it is limited usage. But not ESXi. Unless you are borrowing someone else's license, it is about as far from free as you can get.

Note: I do see that they have a "free" vsphere hypervisor, now. With so few features, I don't think you could call it ESXi (I don't think they even call it ESXi).

Anyways. Let's not beat a dead horse.