Phab vs. Trac

Hi all, Sometimes, the progress on a particular issue is tracked both on Trac and on Phab. What posts should go where? I know Austin is trying to get Trac to be notified when a relevant post happens on Phab -- great. But, if I have a comment, where should I put it? Here is my proposed answer: The Phab reviews are a good place for code-specific commentary/feedback but Trac is better for design issues. A rule of thumb might be to pretend that Phab comments are all forgotten in a month or two, whereas Trac comments are expected to be around in 5 years. Another feature request around Phab/Trac: Is it possible to have a field *at the top of a Trac ticket* that links to the Differential page? Thanks! Richard