I just installed 18.04 on a Dell D520 laptop and so far things seem to be running ok except that I can't get wifi configured. I navigated to Additional Drivers which found the Broadcom BCM4311 minicard not working.
I then checked Using Broadcom 802.11... and Apply Changes. The progress bar show it started then hung up. It never finished.
See Part 2 for the rest of the story