J-20 compared to Pak-Fa

Ok there’s a lot we don’t know about these two seeming as how they are prototypes.
however there’s a lot we can predict based on available information made on:

1. what its designed for/intended use
2. examining needs of that country’s air force
3. things being developed for it
4. basic airframe characteristics.

the two aircraft chose some very different designs and it would be interesting to see where these designs strengths lay.