Here are some Pros and Cons of Mario Kart DS Online so I don't need to write them out too.

Unfortunately, the pros are "no duh you have to have these things" and also unfortunately all the cons are "no duh you have to have these things" too.

The three things I feel it requires but doesn't have are as follows:

1. being able to add friends from people you play with (figure out what his "friend code" is).
   
2. being able to chat with people you play with.
   
3. being able to choose the people you play with without modifying the friends list.

Shucks