Kubuntu Review and Ubuntu Review
There’s a good review up of both Kubuntu and Ubuntu over at Desktoplinux.com. The writer doesn’t seem to find either a perfect fit. Ubuntu is Gnome based, Kubuntu is KDE based. The versions reviewed are 5.10
Ultimately the writer suggests Suse Linux 10.0 or Xandros as a desktop workstation, Mepislite or SimplyMepis for a new user and OpenSuse for a server-based linux OS.
I’m sure there are many opinions, but one good thing about Linux is the variety and the ability to find a distro that you’re comfortable with and that suits your typical workflow and the task you have in mind for the machine. Basically, linux can be what you want it to be.