As well, AC have made a wise choice, going with the GENX powerplant instead of the foreign (RR) one.
In service life so far on the pre-production Trent 900s pulled from the A380 has proven that they have premature heat and wear problems.
For reliability and fuel consumption, the GENX technology in the core machinery of the LPC, HPC, LPT and HPT is based on the more advanced GE-90/115 series.
The core machinery of the RR Trent is based on much older technology.
GENX, the best of 'both worlds', GE and Pratt.