Licensing is unfortunately part of the sw strategy for the ASR9000.
One common question always asked is whether licenses are hard enforced. The answer is NO.
If you want to evaluate a feature in the lab, you're free to do so without a license. If you like to run a licensed feature in production environments,
then you need to obtain the proper license.
To unraffle some of the difficulties as part of the licensing, the following white paper is very useful:
http://www.cisco.com/web/Cisco_IOS_XR_Software/pdf/ASR9000_SWE_User_whitepaper.pdf