This film is a nice try by Ms Nora Ephron. Its best value is, of course, the fact that it is based on two books, themselves based on true stories. However, I found Ms Streep too caricaturesque, notwithstanding the fact that the real Julia Child was quite a histrionic character herself.
Mr Tucci (in the role of her diplomatic husband) is totally wasted. Stanlely Tucci is a great underrated actor (and sometimes director). However, he is simply wasted here due to the rather unattentive script by Ms Ephron.
Amy Adams is ok, but also overacted. Chris Messina's appearance is not worth discussing about. Just to compare (and I believe comparisons are actually the best way for non-expert evaluations, and not "hideous" as a known adagio suggests), I have also seen Merryl Strep and Alec Baldwin's formidable performances on anotheer film on a row. The latter film is mature, with lots of humor, simply impeccable performance by Meryl (as most of the time) and also by Alec.
When watching "Julia & Julie", in spite of being a film on cooking, I did not "sense" either the smell or taste as in other movies on cooking and food, mainly, the great German "Bella Martha" (later in a hideous remake with Catherine Zeta-Jones and Eckart!). Another great film is about a restaurant (I think "The Last Dinner"), probably the last film great Vittorio Gassman acted on. In both these films you can almost smell and taste the food; but that's just embellishment...the films are great: Script, photography, direction, acting.