I'm an average user who is interested in switching to a Linux distro from Windows XP at some point in the near future. I've used Windows OS's pretty exclusively since about 1993, and I've heard that all of the Ubuntu distros are very good for Linux noobs. I am concerned about system resource usage, but I also want something that looks and feels similar to what I'm accustomed to. Is there a significant difference between the look and feel of Xubuntu, Kubuntu, and Ubuntu? I've already ruled out Edubuntu since I don't need a lot of those software packages.