Glad to see you've added the option to customize panels on the welcome screen.
This is really a nitpick, but my only suggestion would be to put the option for "make it look exactly like it did in 16.04" front and center.
I could personally care less what the default layout is as long as the traditional (Applications/Places/System) layout is available (which it is). I could be wrong, but I suspect there are many users who are immediately going to switch right back to the original layout upon first boot, so it would save them some time.
I got very nervous the first time I booted into the 18.04 beta and saw that the menu was changed!