No much drawbacks of virtualization. Most of the big companies are going to virtualization. You might share the resources with other servers, but that's not a problem. For an example if you host your server in virtualization pool, you don't need to worry about the down time too. If one of the ESX hosts/or Base hosts go down, server will switch over to another host and run without any down time.
Please check the following article. It has basic information about it.
http://www.datacentertalk.com/2012/0...irtualization/