My review (and rating) aren't based on my being a fan, which I am. There are episodes in this series that are frankly not all that great. But even those have value because they add layers to the character's stories, relationships and plot arcs.
This episode is IMO the best of the series, closely followed by "Objects In Space".
Written by Tim Minear, the interlaced plot lines are beautifully conceived and edited. In one we get a straight forward catastrophe where the crew, and mostly Mal, are faced with an agonizing death. But instead of chopping through to a simple predictable outcome, we see relationships strained to the breaking point, unrequited yearning, and two twists.
In the second plot thread, we see how the core crew (Mal, Zoe, Wash, Jayne and Kayley) are brought together. Shiny.
The third, less obvious, subplot is Mal's love affair with Serenity. Their first meeting, his against the advice of others head over heels embracing of her, and the slow assembly of her working order and crew.
The artful interweaving of these threads is incredibly well done, and offers layer after layer of characterization and relationship details that make it rich.
I love the intended broadcast order of the series, but an argument could be made to make this the second episode.
Added icing to the (protein) cake are the multiple iconic lines that live on even after the show has been off the air for over twenty years.
Keep flying.