Probably my biggest complaint about the new series is the total lack of motion. I'll admit that I haven't seen every episode, but what I have seen is almost entirely onboard the ships. There is no sense that they have a destination, or even that they are moving anywhere at all! In the original series, the fleet was constantly in motion, the Cylons dogging them every step of the way, and they had an ultimate goal, "a shining planet, known as Earth."
And what they've done to Baltar! In the original series, Baltar was the devil himself, an evil genius plotting the destruction of his own race. In the new series, Baltar is just a goof. There doesn't seem to be a master, evil villan. No Baltar, no Imperious Leader, not even Lucifer.
I'm also a bit annoyed that they seem to have abandoned the entire Colonial measurement system, using English terms like minutes and years instead of centons and yahrens.