I have only flown F twice; FRA - DOH and return. The greatest thing was the F lounge in DOH and a better choice of wine. The rest seemed J to me, especially the menu which was essentially the same as J. The onboard bar was for J too; us F passengers had a long walk!

And the FRA lounge (a LH one) was rubbish.

Al Baker has said they are making J the quality product and there is no need for F.