I had the whole 3-seat center row on EZE-DFW on the 763 a while back. I couldn't really get that comfortable - specifically because the FA "strongly encouraged me" to fasten my seat belt so she could see it, ha.

I would much rather have a J seat. Now, if the J seat was, e.g., $4K R/T and the center seat was $1K... I would have to think about that.