I am one who doesn't think any Arthurian movie can top Boorman's 'Excalibur'. With that said, this movie is not all that bad. The story has most of the core elements of the Arthurian legends. It has a few interesting plot twists which are worth viewing if you are a die-hard fan of the legends. It's no masterpiece, but it's a low-budget TV movie and not a high-budget motion picture. Most of the dialogue and acting is purely professional and Shakespearean in it's approach. I think it could have been cast somewhat better however, the characters of Noah Wyle (Lancelot) and Sean Patrick Flanery (King Arthur) should have been switched. I can clearly see why this alone receives mixed reviews.
Guinevere surely won't win any awards, but for a single viewing it is entertaining to the right audience.