There are three parts to this question:
1. Is WIQL faster then using TFS Web Service API for getting large result sets back?
2. Are the capabilities of these two interfaces same or does one provide more options then the other?
3. Is there a way to get multi-level work item hierarchy from a single query in either of the options, like this:
Get me all Features
Get me all its children PBI
Get me all "Linked" Impediments
Get me all "Tested By" test cases
Get me all "Linked" Tasks
Thanks,
Asif
Asif Sharif President eDev Technologies