Dunno about F to HKG, my company wont pay for it, but I had an involuntary downgrade from DOH to HKG because J was fully booked out. They gave me 4 seats in a row in Y and were quite OK about the whole thing. However the arm rests in the new y seats cannot go all the way up, so sleeping flat was a bit of a squeeze.
More seats in the premium cabins seems a must to me now!

The premium terminal is a 2 storey building with a large and quiet check-in hall, with very comfy high chairs on the left and low counters on the right. I have to say that I hate having to sit down for premium check-in, i just feel uncomfortable, but well, it seems to be the way now....
There are a few immigration counters after check-in and security. All is very quiet and pleasant, much better then next door.
After that there is a tax free shop, but most pax go straight to their lounges. These are upstrairs. Nice waterfall between the stairs. Gates on the right.
Apart from the J & F lounges there is a gaming room, a nursey, claok room, prayer rooms, business centre etc. All very nicely done.
The F & J lounges are in the 'along the windows' style, similar to KUL. J is the busier one. The J lounge is normal, with plenty of staff carrying drinks around and announcing flights. The smoking room is too small late at night. Wireless is available.
The F lounge has overnight beds in several rooms. This looked like they have never been used and it was quite nicely done.
Furthermore it offers a spa with a communal hot tub (can seat at least 8, but is not filled with water just yet), a sauna (which was 65C when I was there) and plenty of showers. I have not been able to locate a gym yet....
It will be my first comment.

Let me know if you have any questions,

Miles