Well, here at Microsoft, I use the query builder every day. We've used a query builder like this to construct queries to find data in bug tracking systems internally for many years - so much so, that this has become second nature to us.
However, we're wondering whether this really is the best UI metaphor for easily finding relevant work item data for the majority of scenarios, for our customers. So I wanted to take a step back, and ask project managers and other TFS users among you out there:
Please let me know what YOU think of the query builder.