STS-121 completed few minutes before 2009, a nice landing at night.
This mission requested me exactly 16 hours (with a poor use of time skip), and I didn't encounter problems. In my opinion it could be reclassified in three stars difficulty level, because precision and attention are requested, even if grapples are not so difficult for Discovery as for ISS RMS are.
I dream SSM 2007 staff give us a day a complete control of this second RMS, because, when docked, ISS and Shuttle are a unique spacecraft, and could be fantastic for us to have a complete control over all ISS-Shuttle operations.
HAPPY NEW YEAR TO ALL!
This is my proof about last missions completed: