Totally agreed. He was more complex, I think. I guess that a lot of it was to do with forcing Shatner to do multiple takes and tone it down as he went. I believe Nick Meyer referred to this as his technique. Movie Picard seemed a bit different, too... becoming an action hero and all. But really, the same could be said of any captain, from Archer to Janeway.
If I had a problem with Archer (and Enterprise as a whole) its that his attitude seemed too 24th century. Too principled, too by the book, too perfect. It seem far more routine than the 23rd century and they were supposed to be writing the book on exploration.
A very valid point. I'd argue that's part of the reason he seemed so inconsistent - most of the time he seemed 24th century competent and principled, and as you say, bored with it, but then when they tried to show him as flawed or make a mistake it made him seem that much more incompetent and inconsistent by comparison.