Pros
-French worlds are really empty (200 players per world)
- Their good if you do not want to talk to anyone!
Cons
- Unless your french, or very good at it, you will struggle to understand the words used for items and other stuff.
-Banking and looking for items on the grand exchange is a nightmare for non french speakers
-It gets lonely with no one to talk to
And here is an image of me playing in a french world!