The Xrv9k-fullk9-7.2.2 image offers a wide range of features, including:
No Hardware Forwarding ASIC
Licensing
NIC / Driver Sensitivity
Known Bugs in 7.2.2
CLI Differences
Version 7.2.2 is part of the IOS XR 7.x long-term maintenance train. It introduced several enhancements over earlier 6.x versions: Xrv9k-fullk9-7.2.2