My wife lost interest like halfway through last season. Unfortunate since it had a lul for an episode or two before it developed its awesome ending.

Season 2 is excellent...except for one very dumb plot line...when you get there you'll know. On the whole, it is great.

Like marx2k said, I liked it throughout. There were some slow parts throughout though.

I do like the alternative history aspect of the show plus the sci-fi aspect.