UTM is alright, but the GUI leaves a lot to be desired, which seems to be a commonality between desktop hypervisors; I have never liked Parallels and VMWare Fusion seems to be rotting on the vine and has its own equally baffling quirks. I would really like not having to shut down all of my VMs and close their windows to get the "library" window back open (shocker, some of us can and need to run more than one VM). I would really like to be able to see the settings of a VM, again, without having to shut down, find the library, and open the settings from there (yes, I know, I can't edit them while the VM is running, I still want to see the things!). It makes troubleshooting and complex configuration such a pain in the ass, that I usually give up.