The trouble as far as I can tell with the Hyper-V setup is that our MSP sold it just to sell it, rather than "Oh hey spend X and build a proper Hypervisor, we'll just use your secondary DC to run these machines"
Which "OK" it works but one of these VM's runs a CPU intensive process, and in only able to use 4CPU's because of the limitations of the host hardware.
If I moved this to "my" (and I use my liberally) XenServer I could allocate 12 cores to it, and 32GB of memory (if we bought more to add into the host) and the team that uses it would never have a complaint.
Its the poor proposals after another that are getting to me. It's just not my place to start looking for another MSP... even though I've considered it.