Can you compare and contrast between "Under The Dome" and "Harper's Island"?

I found a big contrast between those two shows. Under the Dome has been renewed for Season 2, while Harper's Island is only a miniseries. Under the Dome was initially going to be a miniseries, but because the ratings were so high and average viewing was so big, it was renewed for Season 2.

The ending of the first episode of the second season brought back the Harper's Island style when an unknown killer killed Angie.

Harper's Island lasted only one season and Under the Dome will end after 3 seasons.