I started watching this series when it first aired. I love that aliens try to terraform the planet and turn us into them. I liked the notion that they were having almost as much trouble transforming humans as humans were having in stopping them. Some of the cast was really well chosen. I've seen Peter Dinklage in several movies and it was great that they chose a little person for a key role without making his dwarfism a focus. Being the most popular character in the Star Trek franchise makes Brent Spiner sci-fi royalty!
Unfortunately, Spiner and other characters barely get any screen time. The less interesting characters, played by Brian Van Holt and Carla Gugino (who's gorgeous. If you want to see how gorgeous, watch "Sin City"), get undue attention. Apparently, Spiner's Dr. Fenway was to take over leadership of the group in season 2. It's ridiculous that they didn't give a big role at the beginning. Star Trek fans would watch the show just for him, I think.
The dialogue is uninspired. The first season goes by and you never see a full-fledged alien. Sadly, the best episodes were the ones that never aired. Finally, there's some real excitement: a half-alien vigilante, vegetables with human body parts, Alienville!
I think the main reason this series didn't do well is that you had to watch each and every week to know what is going on. So if you didn't catch the first one... Remember what happended to the "X-Files?" The station should've at least given them a few more episodes to end the series properly. There are some special features to watch, but if you liked this series and wanted closure, you won't see a wrap-up episode here.