I've been a big fan of the Shardlake books for years and had been desperate for a TV adaptation long before this series was even announced, so naturally I was very excited to watch.
I thought Arthur Hughes was terrific as Shardlake - top tier casting and despite my reservations about it I do hope they get to make more as I'd love to see him tackle the other stories.
In terms of the main plot it was a faithful enough retelling of the story, a few bits missing or combined and some liberties taken, but the main thrust of things was there.
The colour-blind casting didn't concern me like it seems to have concerned others, however what did irk me was the irreverence towards accurate architecture. The monastery buildings looked painfully European and sure enough the series was filmed I believe in castles in eastern Europe. For me personally, this took me out of the world a bit. The landscape as well just didn't look right - maybe it's because I grew up near the marshes of Kent and East Sussex so I know what they look like ... the marshes of Disney's adaptation looked more like something out of Lord of the Rings. I wonder if anyone on the production team actually visited the area or did any research into what the south east coast of England was like in the 1500s.
I'd also echo what someone else has said about how in the books Sansom really gets across the arduous, slow and often filthy nature of travel in Tudor times, whereas here characters do tend to just zip around. I imagine that's because the producers only had 4 hours to tell the story so couldn't indulge us too much with overnight stops and muddy, rutted roads - but still, it bugged me.