Windows XP Professional Edition has these features above and beyond XP Home
* Includes extended support for security between multiple users on the same machine.
* Better support for peer-to-peer networking, plus support for joining a "Windows NT domain."
* The backup utlity is installed by default.
* The Professional edition includes the following components not found in the Home edition:
o Administrative Tools (in the Start Menu and Control Panel)
o Automated System Recovery (ASR)
o Boot Configuration Manager
o DriverQuery
o Group Policy Refresh Utility
o Multi-lingual User Interface (MUI) add-on
o NTFS Encryption Utilitiy
o Offline Files and Folders
o OpenFiles
o Performance Log Manager
o Remote Desktop
o Scheduled Tasks Console
o Security Template Utility
o Taskkill
o Tasklist
o Telnet Administrator
* Provides support for multi-processor systems (2 or 4 CPUs), Dynamic Disks, Fax.
If you are using this on a regular private home computer and have to pay for this then XP home will run just as fast as pro.
As for who likes Vista better? Some high end gamers using DirectX 10 maybe. Microsoft and people selling computers like Vista the most.