Recommended specs for Gutsy

[chombee]

Is there a recommended specification for a computer to run Ubuntu Gutsy
well, detailing the hardware you need to run it well? (Without needing
the new graphical effects).

I found this wiki page

https://help.ubuntu.com/community/Installation/SystemRequirements

which has specs for Feisty. But here the recommended system requirements
are (to run a graphical version of ubuntu well):

* 500 MHz x86 processor
* 192 MB of system memory (RAM)
* 8 GB of disk space
* Graphics card capable of 1024x768 resolution 
* Sound card
* A network or Internet connection 

In my experience that is totally unrealistic. Certainly a standard
install of Ubuntu will not run well with less than 512MB RAM. I recently
setup a PC with a 1.7GHZ CPU and 512MB RAM and users complained that it
was too slow to use. I thought it was fine personally, but I wasn't the
one using it every day, and the same machine with 256MB RAM was
definitely unusably slow (i.e. you could make a cup of tea in the time
it takes Firefox to open, and don't even think about Open Office).

Another PC I've setup has a 2.5GHZ CPU and 512MB RAM and runs Ubuntu
Feisty perfectly well, to everyones satisfaction. So perhaps that
provides lower and upper bounds.

On the other hand my laptop is 1.7GHZ and 512MB RAM and runs Gutsy
perfectly well, even though that's the same spec as the PC that
apparently does not run it fast enough (if you only look at cpu speed
and amount of ram). So what other factors are important?