Yes of course. I'll believe that the 777X beats the A351 by some margin, in fact, it absolutely has to, otherwise it loses its right to exist. A bigger airplane has to justify its bigger operational and financial risk by being more economical than the competition, this is true for the A380, the 777X and any other airplane. If the 777X beat the A380 by any margin, it would kill it.
You are right, except that it is not as clear-cut as you seem to imply. Unless the differences in size and efficiency are large (which, where efficiency is concerned, is certainly not going to be the case between the -1000 and the 779), other features may be decisive. For a fast-growing airline, for instance, availability and capacity may trump efficiency.
The present Dubai air show is a perfect illustration. Whether the 779 will have a better (or worse) CASK/CASM than the -1000 is anybody's guess - at best, we'll know by the end of the decade. Yet, the bigger aircraft was massively ordered by Gulf airlines ...
The A380, on the other hand, is much bigger than its competitors, and I agree with you that it must also be much more efficient to find buyers.
I reckon there are 300-400 production slots available for the 77W before the 778/9 are in full production, will Boeing be able to sell them or will they have to cut the 77W production rate ?
I don't think that's an impossible target because both A350-1000 and 777X will be sold out until 2023-2025 anyway.
I agree, not impossible by any means. The more 778/9s Boeing sells the more the 77W looks attractive due to shorter lead times. There would be an opportunity for the A35J but Airbus seems to be very cautious about the A350 production rate. John Leahy keeps saying he could sell more A35J if only there were production slots.
The increased payload-range is a given, the other 2 statements sound bold, but not unreasonable when you assume they were based on the most favourable case for the 777X, most likely the far edge of its payload range chart.
The only reason why I read it as a slight 777X advantage was
"The airline is looking at a potential order for as many as 40 777X aircraft in a deal potentially worth $15 billion at list prices, the sources said, asking not to be identified."
and not 'The airline is looking at a potential order for as many as 40 777X or A350-1000s...', especially as this part deals with the 'sources'. Also the article deals quite a lot with the 777X and I found the mention about the A350-1000 as an addition by the reporter not the source. Anyway, enough from me about that.
I think an order for an additional 40 aircraft might be a bit to much, afterall it has 100 A350s and 787s as well as orders for 777s, A380s and A330s but they do need an aircraft to replace and 77W and I agree on the question you asked.
Can the 777X hold 18in at 10 abreast or is it a bit less than that, I think SQ might prefer to keep seat widths as standard so if the 777X can't do 10 abreat @18in I wonder if that might be a detracting factor.