I've seen the first two episodes On Demand. Second episode is better than the first, and the series shows some promise, particularly with Rufus Sewell as a really good central character - Tom Builder. They need to get Ian McShane more substantial things to do, his more reserved role makes you long for his years on Deadwood. There are some other good characters, but the quality is a little uneven.
It's fairly melodramatic and lacks the A level writing and directing of some of the great historical cable series like The Tudors and Rome, or even Spartacus, but it could end up to be not bad.