Well, you will need to audition the two side by side for yourself and then decide. The Z has better bass while the F is focus more on clarity. The Z is more energetic but slightly darker tonally while the F is flatter and very neutral. This leads to the Z being less accurate but more enjoyable to my ears. Still, they are in the same level sonically, but just different. Turok should share his impressions as well. Operation wise, the F is much quicker and better interface.
Yes Purk , I agree with you.
The F, sounds more refined, and this shows that Sony is experimenting with different/better SQ.
For me, the Z is more fun and less fatigue, but if you want the pie in your face with all the extensions , F is your answer, and what a clarity. I am still amazed by the sound I am getting from the F.
I think Sony was smart to change/tinker/enhance the SQ of the F and distinguished it from Z, as this will satisfy more people, and for me both are enjoyable.
There is no one better than the other, but I like this better than the other is a better way to put it.
Hope this ends the "F vs Z'.