Underwood is not and will never be Francis Urquhart, but you can't say it's not fun to watch.
Urquhart, as portrated by Ian Richardson, was a very Shakespearean character, which would be hard to translate into American ground.
As a character, I take Urquhart over Underwood any time, but one thing must be admitted that the original HoC was essentially one-man play with other characters being a mere props and in many cases not very developed ones. Roger O'Neil was just a pathetic drug addict, while Russo was more complex. Elizabeth was pretty much a Lady Macbeth in modern costume and American Stamper is far more developed than the original one, although it was delightful to watch Colin Jeavons's creepy performance.
Good analogy with King/Dunbar. Both strikes me as very well-meaning but not competent in political play, although Dundar seems a little more adept in this regard.