One of the key distinctions is Snus. Moist oral tobacco loose or in a pouch. What sets it apart is the type of tobacco is selected to be as low in TSNA's as possible, and in Sweden they pasteurize the snus shortly after it is batch fermented. Normally they use steam, but small batch snus can be treated with elevated heat and salt to accomplish this also. This results in a very low risk level.
American dip is becoming noticeably lower in the TSNA content, but it still may reach questionable limits do to continued fermentation due to lack of refrigeration.
Nasal snuff is dry and nasal use tends to be rather harmless, but becomes quite a problem when used orally. American oral snuff is particularly dangerous because of the fire cured tobacco used in most types, much higher cancer risk.
American chew contains sugars and higher levels of TSNA's on average. The sugars can do a lot of damage to teeth by themselves.
So wet snus and wet dip have two very different risk factors, one of the reasons snus users are turning to it.
I personally like the flavor of Copenhagen, best taste by far, but I do not want to have to spit, and the oral cancer risks are far higher than snus.
Gum recession is a problem with all forms of smokeless tobacco, but once again snus is spitless and far more forgiving on the gums and gut.
The modern snus seems to offer the greatest harm reduction, and is one of the reasons that I use it. I ruined my heart smoking, fun while it lasted, and I sure miss it! I still keep a respectable amount of nicotine going with snus, and after 4 years have developed quite a preference for it.
Sorry for the long winded presentation, yet I wanted to distinguish the main differences and preferences between American moist dip and Swedish snus.
I love all types of tobacco, and my wife smokes nothing but whole leaf derived cigarettes. I love to blend tobacco as much as any other hobby I have had. Snus has been banned for Squeesyjohn, and The USA is not far behind, and it still remains one of the safest of the smokeless types, go figure! Smart has nothing to do with how it is being regulated by the EU. American snus such as Camel, is a overly sweet nicotine deprived joke!