The trend seems to be to eliminate the over-size toilets. QF used to have 20% more square footage for the F toilets in the 747s, but as they are being refitted with skybeds the F toilets are getting a mirrored wall for the extra space and minus the 20% square footage. They obviously concluded that the space was better used elsewhere. Another failed experiment are the self-dimming windows, these are also being removed by QF and replaced with a manual blind (they forgot that the boarding passengers on the jetway have a fine view of the F toilet when they implemented the automatic shades).
Personally I find the provision of a nice bench folding down over the toilet seat to be more useful, and CX has one of the better ones of any airline. I don't agree that it is an area for useful improvement. But I do wish they would get rid of the ST pyjamas as I don't like them (too stiff and uncomfortable -- the previous design was much better).