Major differences between CU3 and R2 for AX 2012

We are getting ready to launch AX 2012 at our company on December 1st of this year. In September, we updated to CU3. R2 is scheduled to come out on Dec 1st, and we were wondering whether or not we should go ahead and install R2. Does someone have a definitive list of differences between what was added to R2 since CU3 was released? Can anyone make the argument for or against installing R2? We are eager to hear your responses.

Thanks!

Were you upgraded to R2. We have FP (with no Cumulative updates). What are some of the challenges you have faced? Could you share your experience on how to upgrade to R2. since we don’t have any custom code, do we have to go through code upgrade stage?