I've always found performance and stability to be quite lacking with vbox. Parallels and VMWare are both mature, performant, frequently updated, and well-supported, so I see little reason not to use one of those, especially given that I'm using it for work and don't want to wait on a VM for no good reason.
On the other hand, Parallels and VMWare frequently charge for their updates. I rarely find software that has such short license spans. I bought Fusion 5.0.3 in June and they already want to charge me for Fusion 6 (btw. the only version that officially supports Mavericks). Fusion 5 is now dead in the water.
This is okay for me on a single machine, but at scale of a development team, it gets expensive quick.
I installed 4.3 today on my iMac, the machine crashed twice within a couple of hours, it has never crashed otherwise in 2+ years I have owned the machine. Uninstalled, will upgrade Parallels if necessary.
When I was hired at my current company everyone used Virtualbox for their Linux test environments. Unfortunately, part of my job was building/rebuilding custom ISOs, which required long days of tweak->rebuild ISO->rebuild VM.
After I changed from job-installed Virtualbox to the Parallels license I already had, my workflow sped up dramatically. It was easily half the time to go through an install cycle as before. The performance increase was absolutely massive. Since then we've only had more and more issues with Virtualbox that makes it worth replacing at a relatively high cost.
This has gotten a lot better, but for quite a while `vbox` was the thing that made my computer lock up most of the time, especially the USB drivers.