Initially, I didn't think HERO was one of Battlestar's better episodes.
But, after watching it again, I realised just how important it is - and, also why I had issues with it:
It's because it purposefully makes you uncomfortable.
In a way, HERO is a 'quiet' episode. There's not really much going on in the way of battles, but, what HERO does do, is ask questions, that are uncomfortable for the characters, and, for us the viewer
Up until now, the world of BSG has been defined by a predominantly white lead cast. But, in HERO, a black man literally flies in. His call sign is BULLDOG, and who, and what BULLDOG represents on different levels is what this episode is all about.
I don't want to give much of the plot away. Suffice it to say some truths that have been held by both the humans, and Cylons are put into play. Questions that will ultimately play very important parts of the rest of BATTLESTAR are begun.
Let me last say, that, one reason for the 'uncomfortability' in this episode is done whenever a character appears in a series we've become familiar with. Into this, a person, who seems to almost be a fish-out-of-water is thrown in - and given a backstory that appears to be instant.
In the Battlsstar movie, RAZOR, the plot follows another character of this type. Kn Kendra Shaw. But, whereas her integration with the plot threads is woven into the story so as not to 'warp' the fabric, I think that in HERO, Bulldog's character is intentionally dropped in cold.