My thoughts are that any fuel saving is outweighed by the complexity of the engine and its fuel system :-
The basic weight of the 912is is 7kgs heavier than the carb version and this is before the extra weight of the very complicated fuel sysytem is installed which will add more extra weight.
Doing any future maintenance work on it yourself will be ruled out due to the complexity of the injection/electronics needing specialist diagnostic equipment. So any problems incurred in the future are going to cost more.
The conventional 912 carburettor version is in my opinion a far better bet for an LAA machine where the maintenance will be in the main carried out by the owner/s. I am all for keeping it simple.
This is before taking price into consideration, the simple fact is that the 912is intial cost is 5K more than the 912uls!....it is a no brainer IMHO