I've haven't gotten around to watching Firefly (it's in the Netflix queue), and frankly at this point there is no way it can live up to the hype so many people have given it. Which only increases my hesitation to watch it.
The Defiance show is okay. It's not great, it's not terrible. There are a lot of standard, cliched, storylines, but I pretty much expect that on all television shows these days. It certainly beats the 47 channels of reality shows.