Have you benchmarked your bare-metal vs. VM systems? I think you may be surprised how much performance you're losing. If you're not losing any performance I'd be interested as to your setup.

Also, the article discusses VPS systems which are generally much different than installing a VM on hardware you own.

I'll admit that the last time I tried to run an IO intensive task on a VM it was about a year and a half ago. (VMWare ESXi)

I think the processors installed in that box didn't support IO virtualization.