Working with vmware is very easy but if you use linux you can prefer kvm so I did. Kvm is more leightweight and if you get the shortcuts it is easir then vmware workstation. When you migrate from vmware to kvm or u get a vmware appliance it is better to convert disk image because qcow2 gives more features then vmdk in kvm. Bu if your disk images are split more then one file u have to joint them to gether while converting vmdk to qcow2 .
$ qemu-img convert -O qcow2 Debian\ IOL-s00?.vmdk cisco.qcow2