I have been checking out Lubuntu 12.04 and Xubuntu 12.04 for my brother in law. He has a Dell Inspiron 1000 with 512MB of memory. He was using XP, but runs all the time into issues and now his wired network stopped working.
During checking the Ubuntu systems using Virtualbox, I observed a somewhat strange issue with Lubuntu. When starting Conky the CPU load increases to approx. 23% and comparing both systems and my host Ubuntu system that seems strange.
Lubuntu cpu=23%, mem= 88MB, no swap
Xubuntu cpu= 5%, mem=173MB, no swap
Also the host running Ubuntu 12.04 has a cpu load of 6%.
I like to install Conky, but it does not look very feasible with Lubuntu. So without a possibility to reduce the cpu load for Lubuntu, I have to go for Xubuntu.