For workstation stuff? QEMU/KVM is just fine. What you get with VMware is their "enterprise-y" features that aren't necessarily easy or available with QEMU, such as high availability, failover, backups, shared storage, software defined networking, templating, PCI / USB passthrough, etc.
However, there's already a good solution that leverages QEMU/KVM as the engine, giving you all that stuff as well as a nice web console for configuring it all, and an API you can use for automation: Proxmox VE - basically Debian with QEMU/KVM and a lot of tweaks and such to make it work properly on install.
I use this as my base OS on my desktop, so I can virtualize Windows and pass through a GPU, sound device, and specific USB keyboard / mouse and PCI-attached SSD. The OS boots from a VM disk which I snapshot regularly in order to be able to roll back Microsoft's compulsory dipshittery if they break stuff. I also have a second cheap GPU from Ebay (a Quadro M4000) so I can have KDE Plasma running on a third display and have a Linux desktop as well as Windows on the same box, both running at bare metal speeds.
I just wish RAM wasn't so bloody expensive so I could throw another 32GB in there, and it would be perfect.