I think they made cylons look like humans to explore contemporary issues like counter terrorism, etc.
Originally I was really disappointed. I had a hard time getting into it. It was just really dramatic (the original had a lot of spoof and sideline comedy which I really liked) which I'm not used to after Stargate and Star Trek TNG. And their culture is so clearly Western, which I saw as a cop-out.
But I like the actress who plays the president (she was Donnie Darko's mother) and I like the Doctor with the long hair who is borderline crazy (even without seeing a cylon woman no one else can).
Now, after I'm used to the style and am getting into the story more, I'm really beginning to like it. The religous angle is so rarely used in modern science fiction, except perhaps as Frank Herbert used it, that is, as a method for control or as a sign of a 'primitive' culture. I really like how they explore the Hellinistic-ish religion and fulfillment of prophecy, and the conflict with Adama who doesn't believe.
And I especially appreciate how they treat the red shirts. That is, they aren't losing a crewmember at the beginning of each episode like a certain other series that shall remain nameless. There's just alot of attention to detail, both science and people related, which seems so rare in today's science fiction, literature included.
However, they changed the series so much that calling it Battlestar Galactica really is a misnomer, and rather unfortunate in my opinion. It really is it's own entity.