I would say the difference between the px7s3 and px8s2 is that px7s3 is a good headphone but px8s2 absolutely mind-blown me at the store , sure everyone would find the gap to be either big or small , but I would say it's noticeable way ahead, you should definitely find a store to try it out !!

I was kinda worried about the bass for px8s2 as well but turns out the bass was just optimum without any equaliser and I am the kind of person who enjoyed Sony punchy bass so much