Yes, I said it, InfoPath sucks!
I started working with InfoPath back in 2006 and found it real easy to learn.
It is handy for creating simple forms, but nothing beyond simple.
Why?
With the most basic computer knowledge, you can open a form and view all of its contents!
Why is this bad?
Say you have an employee appraisal form. In this form, you have a field called Manager Comments. What if you didn’t want the employee to be able to view the contents of this field?
“Ohhh, I’d create a Rule to handle that!”
Wrong (sort of)!
If the employee opens the Form Library in Explorer View, right clicks on the form, and opts to open in Notepad.
The employee can now see every field and value in that form. Yes, it would be a mess of XML, but…
To get around this scenario, I had to write code to submit the sensitive fields to another List.
*update*
Found one more issue.
In a Form Library, if you click on Connect to Outlook from the Library tab, all of the XML of the forms is displayed in your Outlook preview window.