As far as pilots go, the mini is pretty good. A lot of characters are introduced with what I felt was a minimum of exposition; there's a lot of world-building that's pretty seamless; the threat of the Cylons is real, present, and immediate.
That said, the mini has a lot of issues. I'm assuming they hired some new costume/make-up before the show went to series, or RDM had a talking to the ones that were there - everyone looks horrible. Adama in particular looks older in the mini than he does at the end of the show, for crying out loud. I can't quite pinpoint what is wrong with his hair and make-up, but it is wrong. And we'll not even discuss Roslin's clothes. Or her hair. Or...anything, really.
I mean, Starbuck's hair is just terrifying. I get that they wanted to make her look like a military gal who doesn't really give a shit what her hair looks like, but jeez. (And knowing how Sackhoff feels about having her hair chopped off, I bet she cried as much as when Mira saw her first Delenn make-up.)
Another odd thing about the mini is the way that relationships were set up, usually in a very antagonistic way. Lee vs. Adama, Tigh vs. Starbuck, Adama vs. Roslin (though this one works the best). Conflict is good, sure, but there's this weird probably unintended side effect where everyone kind of comes across as an asshole. Lee and Starbuck especially, which is just...weird. Like, Lee, dude, stop being so mean to your dad. Kara, seriously, Tigh apologized, quit being a total dick. (See they are made for each other!!!!11) (LOL, no, I ship Kara/Anders, whatever.) All the main characters seem like they change a bit between the mini and "33," Baltar excepted, perhaps. But Chief and Cally and Dualla and Gaeta are all pretty much ready to go, which is interesting, but I think makes sense - you're not going to write a lot of background stuff into your tertiary characters, so a lot of their early characterization is going to come from the actors - and later, when the writers expand on them, that's what they're drawing on. So I think there's a lot more consistency with those guys.
I don't have many of these. I was thinking about how Roslin is so quick and capable, so ready to lead when a lot of other people seem to have no idea what's going on (the pilot of Colonial One especially) and it occurred to me that unlike almost everyone else, she didn't just lose anyone. She's already gone through all her losing. She's in shock, sure, but it's the shock of a world suddenly gone missing, not a loved one never to be seen again. It's easier, I think, for her to make that clean break and say, we're done. We're done, our worlds are lost, we're moving on. Let's go. I think Adama coming to the same conclusion is, weirdly enough, his first step on the road to letting go of Zak.