I agree with most of the comments pointing to it as a definite highlight of the first season. I think what I found most impressive, in this, the first crack open of the door in revealing something substantive about what lay behind the facade of Neelix's personality, was the revelation of his vulnerability, weakness, and ultimately guilt. For the first time, he wasn't the hail-fellow-well-met whose equanimity was a constant in almost every situation (excepting The Cloud).
Anger was his justifiable reaction to the individual that was so responsible for the destruction of his family, the subjugation of his world, and his own seeming death sentence. But while warranted, we come to see the what and why that is behind the virulence of his implacable rage. That the shame of his own acts and decisions to have run, rather than join the fight in protecting Rinax that have haunted him for years, can no longer be hidden by a positive farcical facade. He is forced to voice truths that very few people alive are aware of, certainly not Kes. I don't recall if Neelix stated it directly, but I would have no doubt that he had felt that he should have been consumed along with his kin. Instead, he shut himself off in the solitary loneliness of a tinkerer's existence, probably without the ability to see himself worthy of anything more than simply surviving, no hope of redemption or the promise of anything transformative due him, at least until he found Kes.
I'm not sure I would rank it above Mortal Coil, but what is certain is that after this episode, any viewer that wasn't irrevocably predisposed to always dismissing him as a clown, could see clearly the outline of a multi-faceted personality whose compelling story had many more chapters yet to be told.
