All of them are Oracle now and Virtual Box is pretty good?
It really isn't. VirtualBox was always mediocre compared to VMWare, and ever since the Oracle acquisition, I haven't heard of any major new features or performance improvements coming out of the VirtualBox team. Though, given what Oracle has done to its other acquisitions, benign neglect is a pretty good outcome.
lol? VirtualBox has been maintaining its release cadence since the Oracle acquisition in 2010 (almost 7 years ago!), including 2 major-version releases. It seems to be one of the few parts of the Sun family that hasn't been mucked up yet. I keep waiting for Oracle to give it The Oracle Treatment(tm), but heretofore, that hasn't occurred. The VBox guys must have their cubicles hidden really well. ;)
If you want to see the "major new features" implemented, you need look no further than the changelog. [0]
And FWIW, I've tried VMWare Workstation several times and even own a copy of it, but VirtualBox has been and continues to be the most reliable, simple method of virtualization for me (and several of my colleagues). The VMWare drivers/tools are frequently broken by kernel upgrades, the interface is clunkier and more demanding (including requiring hosts to run a couple of background daemons; VBox operates fine on hosts with just the drivers installed), and the performance, while better in some areas, is much worse in others, making it a wash for general use.
Virtualbox... good? I don't think so at all, it's networking and disk IO performance is horrendous, as much as I dislike VMware - Fusion is miles ahead of VirtualBox in all ways IMO except price. But now we have Xhyve & friends which is truly fantastic.