The experienced killers struggle with their emotions to kill people (used to be arrogant and killed people for fun in their youth); they do not gloat with glee on the number of kills they have done so far - rather they are filled with remorse and fear.
Whereas the amateur has never killed a soul so far but boasts of having killed 5 people (when truly his eyesight / aim is quite bad). Surprising to find a cameo by the first Dumbledore Richard Harris in this movie :) (can't imagine him in any other role) !!
English Bob seemed like a very cool character but in the end his story didn't lead anywhere and I was very disappointed in that area of the film. Other than that, a lot of the plot moved far too slow for my liking, and I found myself very bored with this otherwise competent and mildly interesting film