I finally decided to take the plunge and try using Virt Manager. For years, I’ve seen Linux users telling us VirtualBox hold outs to switch, but I never did. I like VirtualBox and am very comfortable with it for my usage.
This past weekend I took the plunge and had a serious look at using Virt Manager, and I’m here to say that it looks like Virt Manager is pretty freaking awesome.
Maybe you all were right. 
Well done.
I switched a couple of years ago, after I had to deal with extra non-free bits in VirtualBox, causing me trouble. No point - Virt Manager does it all, and it’s in the repo 
by the way Virt manager is only a GUI for KVM.
KVM itself has feasible performance benefits:
Virtualbox is type 2 (software) hypervisor,
KVM/Hyper-V are type 1 (bare metal) hypervisors.
there seems to be no sense in using virtualbox in linux as KVM is natively available, it’s better in many ways.
On windows one should use Hyper-V where license (Microsoft) allows.
Virtualbox seems to be for windows home or a mac where there’s no other way.
The best is about the kernel modules you not need anymore the same way as on virtual-box.
A kernel change always affects the software, also with KVM, however since we change quite often the usage seams more smoth.
Also full screen between different os’s is smoth, without installing the additional software for every version.
I never looked back.
How is 3D video accelerated in guests with virt manager?
I found VMWare Player better than VirtualBox with Linux guests (FlightGear, OpenGL), and had a preference with Fusion vs Parallels on macOS years ago (not sure on specifics)