I didn't care for Falling Skies
at all. The first season was pretty badly written and had few interesting characters, so I didn't even bother with the second. (The stupidest thing that stands out in my mind was the plan from the first-season finale where they were going to take out the aliens' huge four-legged construct by splitting up into teams to blow up all four legs. Umm, hello? Haven't any of the writers ever had a chair leg break under them? All they had to do was blow one
leg and the whole thing would've toppled!)
Besides, the two shows are very different. Falling Skies
is a guerrilla-war story about fighting off alien invaders who've conquered Earth. Defiance
is an immigrant story of various cultures, including humans, trying to build a life in a world that's alien to all of them.