This is the first sci fi series that I have seriously become hooked on since Star Trek, (and I haven't watched Trek in years). It takes the invasion theme in somewhat different directions, but has done it in a very exciting way. It also borrows from soap opera format, where it continues the arc throughout the entire year run of the series. The CGI definitely doesn't overcome the plot or the characters, except for Nim, the fledgling creature who is a pet with definite attitude. (Anything that would show what he really thought about the neighbor's yippy dog is A-1 in my book.) He was a stroke of genius.
I am left at the end of the finale asking questions (intelligent ones, I hope) and crossing my fingers and toes that NBC or someone else (Sci Fi, maybe) will continue to run the series and answer those questions.
A really great, classy show.