The User Task List Web Part vs The Content Query Web Part

I have a requirement for a task roll up web part. I have an Event Receiver that spawns a new task list for every list item in another list. The receiver looks in to a People Picker Field (SPFieldUserMulti)and creates a new task for all of the users in the field.

We wanted a web part that would only show the user's active tasks to place on the site home page so that the user could seamlessly find the tasks assigned to them, without having to transverse a bunch of task lists. So how to do this? There are a couple of different ways. If you are looking for a quick Out Of the Box (OOB) way, you need only drop the User Task List Web Part (UTLWP), from the Social Collaboration Web Part Group, on your page and you are done!! The User Task List will look in to the site and show all of the tasks, that are not marked as complete, in a list. Very easy and very quick.

The other way to do things is almost as easy, you drop a Content Query Web Part (CQWP), from the Content Roll Up Web Part Group, on your page. You set the query to list Type Tasks, and then configure the Additional Filters to look at the Assigned To site column with a setting of equal to [Me]. The next filter should be the Task Status site column, and set the configuration to not equal "Completed."

Now we have two web parts that will show the tasks assigned to the user throughout the site, all in a matter of just a few moments! Very cool!

So... What if we want more? What if we just want the tasks assigned to the user, but we want them to be current. In other words, we want the task to be assigned to the user, have a task status set to anything but Completed, and the due date must be greater than today.
Now the ease of the User Task List Web Part falls away. For some reason, the makers of the web part didn't add a way to easily change the configuration. It is not possible to change the internal query of the UTLWP to add the extra filter of Due Date. Bummer.

However, the CQWP can be very quickly configured to make this extra change happen, we simply add another filter to our query that sets the Due Date to be greater than or equal to [Today] in the Additional Filters section. Blamo, that easy.

Now, what if we have task lists in other sites within the Site Collection? What if we want to aggregate these tasks to the page in the root site?

The CQWP base query uses the SPSiteDataQuery object to search through all sites in the site collection for those items that meet the search criteria. So, it AUTOMATICALLY will aggregate the sites and display the items that meed the query criteria. Dead easy, right?

The UTLWP will only show tasks in the current site. Big bummer. BUT, you can change the base query from the standard site query to a SPSiteDataQuery by doing a few minor steps. First you drop the UTLWP on to your page. Then click the down arrow on the upper right hand of the web part. Select "Export." This will download the web part on to your local computer as a .dwp file. This is just an XML file of the web part's settings.
Open the DWP file in a text editor, preferably one that will color code and format the text as XML. This is not a requirement, but it really does make it easier to read.
At the bottom of the file just above the closing </WebPart> tag put in this tag:
<QuerySiteCollection xmlns="http://schemas.microsoft.com/WebPart/v2/Aggregation">true</QuerySiteCollection>
Save the file and go back to your SharePoint page. In the Web Part selector ribbon, there is a link to upload a web part. Simply click on this and upload the dwp file you just manipulated. Then just drop it on your page.
BINGO!! You have a UTLWP that will show all the uncompleted tasks for the user in all sites in the site collection.

So, in the battle between these two very useful web parts, who wins? Of course it all depends on your business needs. My particular business needs point me towards the more flexible CQWP, because I need to show the tasks for the user that are not complete, and not overdue. It also allows me to add another CQWP on the page to show the user the tasks that are not complete and ARE overdue. The UTLWP, while very useful, does not allow me to do that.