I've used VirtualBox / Vagrant to locally develop sites on the following CMS's and platforms: Magento, OpenCart, WordPress and Concrete5.
Of all the above, Concrete5 sites are by far the slowest, and can take in excess of 10 seconds to fully load pages. If logged in, pages can take over 20 seconds.
If I enable caching during development, load time is cut to around 6 & 14 seconds for not logged in and logged in sessions respectively.
I've customised my setup for Concrete5 in an attempt to speed it up, even allocating 4GB of RAM to the VM. I usually allocate 2GB to all other VM's which use the other platforms. Allocating the extra RAM achieves absolute nothing in terms of performance.
I've been using CentOS 6.4 as guest OS...
As mentioned above, it only seems to be Concrete5 that is giving me problems. Has anyone else experienced this, and if so, do you know any particular reason why it is so slow?
Depending on how you have setup your virtual machine, in *Unix environments, you can achieve a big boost by using an opcaching extension in PHP.
I am using OPCACHE with PHP 5.5.x which I found Concrete5.7.x to run really well and against PHP 5.4 or 5.3 using APC for opcaching, the difference is visible.
As of how Opcaching extensions work, it is best to tweak it's settings so it will keep as much as possible of precompiled scripts in RAM, as that boosts any php applications.
To mention also, I am setting Concrete5 for suitable for development and don't have problems for things not changing.