Hi Safari7 I have limited experience in F but I would say that, although I prefer QR business class to Emirates, I was very underwhelmed by QR's F cabin. It looks a bit dull and cheap in there, with huge amounts of space that no-one knows how to use.

I found QRs F seat very comfy and slept like a wooden man so A plus for that.

MarkLHR is right about the food but in my opinion QR's J food is well ahead of Emirates anyway, so you should be happy with that.

Doha Premium Terminal has a bit of wow factor for the first couple of times, so on that basis give it a try. (Later on you realise its limitations). I find the dedicated shopping area quite useful, and it means that unlike DXB T3 you don't have to exit the lounge and fight with the crowds of shoppers for last minute gifts etc.