While I would love to love ESX.....there is one thing that talk against it: Running local storage.
VMware earn their money on their Enterprise customers which use SAN, e.g. i SCSI, and expensive enterprise hardware hence this is where focus is....and it shows!
It means ESX have a limited hardware support and often terrible performance on local-storage-setup. One exception is USB pass-through though, which Hyper-V doesn't have.
You can get good storage performance with SSD or/and have a lot of hardware storage cache to compensate for the terrible ESX-local-storage handling.
To get a decent performance on ESX with local storage you have to virtualize something like FreeNAS to deliver iSCSI and pass-through your local storage adapter(s) to FreeNAS so ESX doesn't touch it directly. Then have ESX use the iSCSI that FreeNAS deliver, which is virtualize by ESX itself, a long way to just get decent local storage!
You can also pass-through a whole disk to a VM (using a RDM-file on ESX), but then VMs can share storage and not have a VM in one file, which it many cases is on of the biggest reasons to virtualize in the first place.
Another thing to prove my point ESX doesn't support disk with 4K sectors which has been around for a long time and is the future. Hyper-V (and for that matter FreeNAS) does of course. But again ESX didn't want to use "5 minutes" to implement it in ESX....I believe the job is already done in the linux kernel, they can just grape it, they don't have to build from ground up.
Compared with Hyper-V where local storage works like it should out of the box with good performance....even support Intel RSTe raid.
ESX is Linux and have a small footprint.....Hyper-V is Windows and we all know what that means, although it's a Core version.
The small-business market is HUGE and can be a good business....but VMware still have to wake-up and smell the coffee.
VMware should put a price tag on ESXi at $125 instead of give it away free and sell 100.000 licenses...that should cover the "5 minutes" it take to implement descent local storage handling. On top of that VMware would get even more fans which would choose ESX over Hyper-V when they one day move to enterprise-class.