The "5.5 generation" claim is also one of the rumors made by one of the Pakistani "big shrimps" on PDF.So, a two-seater?
But, how credible is this guy?
Here is the exact quote from this fellow:
Translation: "This year, the J-20A will have more profound changes and performance, and in the near future, will evolve into the world's only fourth (and a half) generation multirole fighter!"J-20A在今年，将会有更重大的变化和表现，未来不久，将会进化成为世界上独一无二的四代（半）多用途战斗机！