After upgrading to 17.1 I am unable to use VMware 14 to run Windows 8.1. The error is inability to lock enough RAM. I have 12 Gb in the laptop, and 6 Gb is assigned to Windows 8.1. After a fresh boot I am able to launch the VM but within a few minutes, even without any other apps running, it shuts down, reporting not enough RAM. I heard from another user on VMware’s forum that it works in 17.1 Unity but not other flavors of 17.1.
Also, after going to 17.1 my USB audio device stopped functioning. This one is a real mystery because the system appears to be behaving exactly as before but no sound is coming out. There are some 3rd party drivers installed from a non-default repository. The device is working on another 17.1 system which has default audio settings—no custom tweaks to ALSA and Pulse conf, no 3rd party drivers.
This is feedback, in case it is helpful. I am waiting for 18.04 now. The big mistake I made was going down the rabbit hole of inter-LTS releases. I had a good, working install of 16.04, which was doing everything I needed. I should have left it the heck alone. If 18.04 works out of the box, or with a few quick tweaks, I will leave it the heck alone till 20.04 comes out.