When I first started playing with Linux I had a very crappy old computer; I think it was a 286. It was painful to try and do anything in Gnome or KDE, but it ended up making a pretty good server as it was the server that ran this site until late 2005 or early 2006 (I can’t remember). Then I moved onto another machine which was slightly better, a Pentium II 400 Mhz, 128 MB RAM computer. That computer ran a little better in Gnome or KDE, but I became a huge fan of Fluxbox as it ran best and I was able to use it as my almost-primary computer. It is now Luigi, my file/print server.
I got Mario in 2005. It’s an eMachine with 512 MB RAM and A 2 Ghz AMD Sempron. It functions as my main computer and I do nearly everything on it. Gnome with Compiz runs well on it with 512 MB of RAM, but not spectacularly. That, coupled with the fact that some of my Blender files became too massive to do on Mario, convinced me to buy another GB of RAM for Mario. So it now has 1.5 GB of RAM.
Programs load only slightly faster, but that’s what I expected. Afterall, until you have a lot of programs open and you have to start moving stuff onto and off of the swap, RAM doesn’t have much to do with how fast programs load. However, I noticed that the Gnome menus, which had been painfully slow before were now usable. I also noticed that Compiz seems to run more smoothly and the effects don’t take quite as long.
Overall, I’m pretty happy with my purchase. It only cost me $50 and I seem to be having a much better experience. If things don’t turn out that way, I’ll be sure to mention it in the comments.