For pilots, are the procedures different between airframes with different engine options? Lets use the B757 as an example. Engine options are PW2000 and the RB211. As I'm sure they are both FADEC engines we don't have to worry about and mechanical linkages and such. But each engine although comparable in thrust ranges have different requirements from the aircraft. 

As a B757 pilot are the procedures different between the airframes with different engine options?
I can only speak for the Boeing B787, but the 787 Flight Crew Operating Manual (FCOM) indicates that there are slight differences between different engine options. Three examples:


autostart modes (different failures can be automatically detected and corrected for during engine autostart),
warm-up times before take-off and cool-down times after landing,
take-off thrust setting ("GE engines: Advance the thrust levers to approximately 40% N1" vs "RR engines: Advance the thrust levers to approximately 20 TPR" - this also indicates that the primary engine indications are slightly different: N1 and EGT vs. TPR, N1 and EGT).


I don't know though how much these slight differences translate to different procedures, as I am not a pilot.