When I was in DOH a week ago transiting from HBE to ADL (in F/J class), I thought I'd take a look at the 1st class lounge for Emerald FF's, as I will be transiting DOH in Y later this year (only shortish flights though).
Although it was quite a bit smaller than al Mourjan, I quite liked it, particularly the help-yourself approach to food/beverages, which doesn't seem to be available in al Mourjan.
I must say I'm not a great fan of waiter service and tended bars in airport lounges (al Safwa excepted).
Just a few random thoughts...