I would choose Al Safwa above EK F in a heart beat bt then again, I would choose QR above EK in a heart beat too.
I’ve not flown EK F for 20+ years, nor EK J for 12 years - so I can’t comment on EK’s F lounge. However, like you, I would choose QR over EK in a heartbeat.
However the reason for this post - what is the general opinion of DOH v DXB as airports (eg, ease of transfer through airport, flight congestion, etc)? In my opinion DOH is ahead of DXB.