Try CX J once and see whether you can put up with the new seat. However they sometimes use the old slanty seat on the AKL leg so you might not get to try it.

The CX J seat you also have to sleep on an angle, and your feet are sticking out in the aisle, so they can often be brushed or fall off the footstool. So you have the same issues as the SQ J seats, with no upsides of wider seat and protected footwell.

I suspect after you try the new CX J seat once, you won't want to continue using it compared to the new SQ J seat.