I actually use VirtualBox when I'm running Dynamips (it has good hooks when launching network connected clients) - but for day-day productivity, Windows 7 Unity Mode in VMware is pretty great.

I can double click on a .vsd file and have it launch in Visio as a close-to-native app. Also, (and this may sound stupid, but it's handy) the little "Double-Arrow Start Icon" on my Menu Bar is handy for launching Windows Apps.

On my Windows Desktop System I use VMware Workstation because it reliably shuts down and restarts my linux guests, without me logging in to windows. (Though it took me a while to find out out how to do that). I.E. on a windows restart, VMware workstation gracefully shuts down the Client Operating System, and after reboot (and prior to me logging into the Windows Environment - I.E. Before I get to the office) - it restarts VMware Workstation service (not the app), and then restarts whatever Linux Guests I've selected in the "Shared VMs" panel.

This is important, as my Windows 7 Desktop System is now being rebooted by Microsoft two-three times a month for security updates - which I'm fine with as long as my Linux guests are there when I want them.

I can't speak for the OP, but my office chose VMWare over VirtualBox after finding VMWare to be about 3x faster running the unit tests for our main code repository, which are both I/O and CPU intensive.

I had similar findings in my office, with Parallels actually topping the list. I'm not sure if that was a fluke or not, as it was a windows VM that I needed to run, but VMWare definitely surpassed VirtualBox for that and some other tests.

I've used both on my various Macs, and I find that VMware Fusion generally seems to perform better. Parallels Desktop seems to have better virtualized 3D, though, so I've found myself moving more to that.

>> Off-topic, but I'm curious about why you use VMWare instead of VirtualBox.

Faster, integrates much better into OS X, seamless mode, 3D acceleration, better linux guest tools, easier updates, lots of reasons actually.

VirtualBox is pretty good by itself, but I found that VMWare Fusion more than makes up for its (very reasonable) price.

My office as well was a heavy user of VirtualBox until Vagrant 1.1 hit, and then we dropped a pretty penny on VMWare licenses.

One of the biggest things we noticed was a big bump in IO, especially with shared folders. We also experienced random mysterious crashes and hangs with VirtualBox, seemingly related to sleep/wake.

Less technical, but the VirtualBox interface looked like complete ass on OSX for the longest time.

VMware definitely seems faster (I'm running Windows 8 as a VM inside Linux), but seeing as it's a paid product, there'll be choice-supportive bias all over the place.