Release order vs. Flashback order?

Going for a rewatch of 1-6 this weekend.

I've done release order and chronological order, but never done flashback order which is typically watch Episode 4, 5, 1, 2, 3, and 6.

Has anyone done flashback order and if so how did you like it compared to release or chronological?

Further IF you could add one additional movie or portion of Clone Wars what would you add? Total time is 13.5 hours for Episode 1-6, and I think I have time for one more. My thoughts are Rogue One after Episode 3(shows Vader and all that, but also gets you back into the OT more easily).