The trailers for this were terrible

and misleading and the reception very negative - such that I had no interest in it at all.
However it just turned up on TV so being lazy yet with low expectations I watched it and, as it turns out, I thought it was OK.
You mess with the story of King Arthur at your peril but I think if this film had been branded as - Guy Ritchie's retelling of the legend of King Arthur - it might have found a more receptive audience. Also, I liked the setting of much of the film in a crumbling post-roman London. There must have been a long period where the stone built grandeur of Rome was gradually replaced by the wooden building of the dark ages and I thought this was well imagined.