Enhances NASA's EDL capability - every opportunity makes us smarter.
Performance - Large mass - Large ballistic coefficient.
Entry Guidance - Powered flight - Supersonic retro propulsion.
Ground Guidance - How landing, rocket plumes interaction.
Will be the Dragon 2 for Commercial Crew - Stresses will not be a craft that can send humans to Mars. (too small).
SpaceX have been very good at listening to updates and suggestions (sensors on the Dragon), trades for mission success / what they want to accomplish.
Likelihood of success - High level top down - Reasonable likelihood, increased with NASA support. Both NASA and SpaceX understand it could fail, NASA felt it was a good chance of success. Aggressive timeline, worthwhile for participation.