How's it going, TIVIN?
As to XML Notepad vs. XMLSpy - I concur that XMLSpy is more powerful ... However, if compared to Cooktop - XMLSpy still lacks full compliance with XSLT processors - not quite sure if the fix was in place in 5.0 + version of XMlSpy.
Moreover, the XMLSpyFormEditor program needs access to the registry - and as a result XMLSpy throws an error saying that the instance of it could not be created.

admin rights are a requirement
IMHO, XML Notepad is still good for creating data sets quickly and easily ...
Or what's your opinion?
Keep cool!