I can tell you my first impression is mostly positive. They really do a great job of making this very dramatic story compelling and thoroughly modern. Ian McShane plays King Silas, the king of Gilboa. The hero, David Shepherd, is a young soldier/mechanic/musician. The first episode tells the story of David standing up to the army of Gath and their massive "Goliath" tanks in an attempt to rescue two POWs, one of who ends up being the king's son, Jack.
The one disappointing aspect was an implication that Silas's son, Jack, is a closet homosexual. It'll be interesting to see where the writers go with this, considering the close friendship between David and Jonathon in the Bible.
There are major spiritual themes in Kings. One of my favorite characters is the spiritual leader Rev. Samuels. He does a great job playing the prophet and mouthpiece of God. Issues of God's will, courage, envy, humility, pride, and all the other great themes present in the Biblical story are there.
I can't wait to see how this show continues to unfold. It probably won't be suitable for all ages all the time. Even if they stuck to the Biblical details, there are some mature things that happen in the Biblical story.