Best is you look in the virtuozzo forum, and look at the problem the end user are describing.;)
Second think about the processor roadmaps of intel and amd. If you look at this you will see nic and disk i/o virtualizaion in hardware in 2009.
The overhead with amd iommu and intel vt-d will reduce the overhead for hypervisior.
For a homogen Webserver Farm virtuozzo is a good solution. For heterogen application servers it is not.
Think about, that Microsoft is one of the the biggest customer of vmware!!!
How many of the Top 100 companies use virtuozzo?? Ask them. Vmware is used by 100 % of the top 100 companies.
Main problem with all virtualization is you would need fault tolerant system for your esx host. If a host is faulty you have downtime for multiple application servers. Think about 20 , 40 , 60 ,or 80 applications servers are down, because the host has a problem. Yes VMware HA can reboot your VM's
but you have down time. Although think about applications, which run not as a service. This application will not run after the reboot. You have to manually start the application in the vm.
