In terms of a route file, there's no difference. They are just route files.
In terms of route text, they are both using different languages to code the layout. Just like comparing Java and C++.
Java is usually easier to learn and its the first computing language most people learn, while C++ is a bit more advanced and most people learn it after learning Java.
With CSV and RW, none of them are harder then the other. They are just different languages. If you build a route now, you would want to learn the basic commands of CSV first, then learn the more advanced commands such as .beacon commands.