Now, this makes me think. I wanted to install 12.04 Xubuntu for it's long time support availability. Reading through the article made me wonder. I thought, newer is better. They fixed many things, added something nice ... but I didn't consider loss of performance to be an issue on my laptop. Now I am wondering whether my Intel P6200 with 2GB of RAM can pull off 12.04 even with Xfce. Maybe I should stay with 11.04, but download the 64bit version. I was hoping for 64bit 12.04 thought. Heard they are working on some fixes and stuff.
In my experience it is mostly just desktop changes that cause problems. I am running a system currently with just 512 MB of RAM with the Fedora 15 LXDE spin and it is operating fine. Although, this laptop is not that old, but simply came with an insanely low amount of memory.