Hardware information:
Motherboard: Asus P2B-DS
Processors: 2x 700MHz Intel Pentium III, cB0 stepping - 12% overclock (784MHz)
RAM: 512mb Kingmax PC150
Disk controller: Embedded Adaptec 7890UW
Hard drive: 73GB Seagate Cheetah U160 SCSI 10k rpm
Removable drives: 12x Plextor SCSI CDRW, 4x NEC SCSI CD-ROM
Video: 16mb Nvidia Riva TNT (Voodoo Banshee)
NIC: Who the hell knows? I think it's some 100Base-Tx generic NIC with a Realtek chipset. All I know it it works

Sound: Creative Labs SB32 ISA PnP
OS: Fedora Core 4
Anyway, this machine was my desktop PC several years ago and now performs duties as a web/mail/irc server.
Although this machine can still saturate my outbound Internet connection, it's been feeling a little pokey. From the command line the machine is still more than competent but running both Gnome or KDE has been a bit of an exercise in frustration as my dual processor Windows XP box will run circles around it - the XP box only has 384mb RAM but does have a pair of 1000MHz processors.
Anyway, I decided I didn't need all the bloat, I just needed to be able to run some Gnome applications - so I installed xfce4, switched to that window manager and the machine runs like it's on steroids now - considering the machine's getting a little long in the tooth xfce's really breathed new life into it.
How to do it -
1. Install all the xfce packages. Yum Extender or synaptic is pretty good for this.
2. From a terminal prompt, type 'switchdesk xfce'.
3. Start X and enjoy!
If you don't like what you found, 'switchdesk gnome' or 'switchdesk kde' will put things back the way they were.
Screenshots are available at
http://www.xfce.org
My ratings:
Installation: 5 - no problems. yum resolved all dependencies
Ease of use: 4 - it's less feature-rich than either Gnome or KDE but it's also a hell of a lot faster

Features: 4 - will run most Gnome or KDE apps. Gnome or KDE need to be installed for this functionality, though. Many more features than fluxbox or icewm.
Quality of the program: 5 - solid, stable, fast.
Overall assessment: 4.5 - solid window manager, great features, fast.