IMHO, take advantage of the incentives, load Sonar X2 on your WinXP system (if your system meets the requirements) and do NOT load the X2a patch until you upgrade to Win 7 or Win 8.
X2 worked fine on my system while I was deciding whether or not I was going to upgrade to Windows 8 (I went with Windows 7 Professional because of my Desktop system and don't see ever getting a "Touch" screen).
Doug