The big deal about 505 and 507 is specific protection for cam lobe wear. 507 is for dpf and 505 is non dpf. The way the tdi engine is designed, it requires a specific oil to prevent premature cam lobe wear.
Any modern diesel oil can deal with dpfs, but only 507 can deal with cam lobe wear prevention.
In the CR TDIs I don't think cam wear will be an issue since they have roller rockers now.
505.01 oils were also lower SAPS than 505.00. 505.00 is an old standard, it's what my 91 ECODiesel Jetta called for. I'll also point out again that although VW claims 505.01 is enough to protect the cams in PD TDIs, expierence has shown otherwise :frown2:
EDIT: I'll add that my dealer also has great pricing on the Castrol 507.00 oil. From what I've read it does a fine job of protecting the motor, and oil analysis in my Passat confirms it's fine for a 10k oil change interval