Some might have shit software. It's just like the bad old days of a Packard Bell with Windows 98 and XP bundled with a ton of crapware. What about you get Norton Anvitirus, Real Player, Acrobat Reader preloading with system tray icon, Packard Bell / Acer / whatever "troubleshooting" and "driver" utility, sound card special configuration GUI, webcam shitware, get a printer and install the "helpful" bundleware, Microsoft Active Desktop, yahoo/AOL/Ask Jeeves/Packard Bell toolbars in Internet Explorer, all with 128MB RAM and a Celeron with 66MHz bus? (which were screaming fast specs a year ago)
In those old days though, you installed a clean Windows from a warez CD (to save time), good drivers without "helpful" software (not included or crossed out in the installer), actually useful software like winrar, winamp, codecs etc. then that poor piece of crap PC was actually fast. You could also take your chance and clean up the crap manually without a reinstall (quit tray programs, uninstall crap, run msconfig, delete shortcuts)
Well. If continuing the PC analogy, get 2GB RAM instead of 1GB RAM, get 3GB instead of 2GB RAM, get 4GB instead of 3GB RAM (depending on price points) and pay attention to storage speed benchmarks or reviews that complain about slow storage.