2. The beef hot dog has many different subspecies.
a) The Chicago beef is purely of the type created by the Vienna Beef people. it is a class by itself that has nothing to do with the NY style, or the Michigan Coney Island style. Yes, MI (Coney Island). It means the sauce, and also goes with a particular type of dog and bread/roll.
b) the Manhattan all-beef KOSHER STYLE and pure KOSHER are created by a very few companies. They have sizes like 8/lb, and so forth, that does make a difference. Gray's Papaya is a well-known purveyor. Sabrett's is a well-known brand, but it and Nathan's, are all produced from the same meat plant in metro NYC. Best's Kosher style dogs in NJ, and their corned brisket, also set a benchmark.
c) Wisconsin has several very high quality all-beef purveyors. Go to Roadfood for serious discussions on hot dogs.
...
Gilbert's Kosher Hot Dogs, which you can find at a Waitrose or Sainsburys with a good kosher section, is the best I've had. I'm a Yank and it's the closest I've found to that NY kosher hot dog taste.