Whilst I agree that when it is good, EK first is out of this world, the OP does not address what for me is the single most annoying aspect of the airlines' performance....inconsistency. Sometimes you're given an amenity kit, sometimes not. Sometimes pyjamas sometimes not (and to reply to previous comments I've had both kits and pyjamas given on MRU-DXB which is a 6.5 hr flight -sometimes). Some cities offer chauffeur drive, some don't. Sometimes the website works wonderfully, sometimes "a technical error" has "prevented them" from booking your upgrade. Sometimes the service is wonderful, sometimes it's average. Sometimes the food is world-class, sometimes it's average. Sometimes the people at the service centres are knowledgeable and sometimes not at all. The only thing I have found to be consistent is the quality of the wines on board.
I know that inconsistency is something that many travellers accuse many other airlines of as well, but when you are paying First Class ticket prices surely getting consistently good service should be a given...