Tried to run 18.04 in VM's on my work laptop and personal laptop and I'm just getting the same results - very slow responding OS no matter what. I've got guest additions installed as usual and ran updates. I've even given the machine 4 cores and 8GB ram on my home machine and it's still awful to use. I've googled around a bit and seems I'm not the only one but I can seem to find any fixes for it. Anyone else experienced this?