744 RR engines are always are having problems with :
1. attrition liner damage/replacement
2. ogv infill panel seperation/ogv cracking
3. titanium acoustic panel delamination
4. ice breaker panel delamination
5. thrust rev motor failure
6. flex drive cable breaking/seizure
6. thrust rev sense line failure/leaking
7. bleed valve sense line failure/leaking
8. selector seq valve malfunction
9. sense line clamp failure
10. interservices structure cracking
11. N1 fan vibrations
744 GE engines nothing goes wrong except the odd thrust rev does not deploy and a bit of anti ice fluid poured into the cdu can fix this.
GE engines a little bit harder to work on with but a better fuel burn than RR.