Like Barney already said. The 197 has separated tailpipe ends and the 200 has them integrated in the diffusor. Some people just switch them out because they like the look.
Personally I'm not such a fan of the chrome rings on the 200 but that's because I'm a little biased.
Easy and cheap mod to do, and easy to remove if you don't like them. Simply clamped onto the slash cut standard tips. Plenty of threads if you search with links to ones people have bought! I personally like them.
As above, plenty of options available if you did want the tips to be more pronounced. I quite like the subtlety of the standard 197 tips, they sit well with the diffuser and aren't too in your face.