A pefect example would be my 5903 Vs. my 5906.
Same gun, one aluminum frame, one in Stainless steel.
The aluminum framed 5903 does recoil a bit more but not so much to matter that much.
The 5906 is more rock solid when firing but is noticably heavier.
I think it's 37.5 oz. in SS compared to 28 oz. in aluminum.
Depending on the design, aluminum can fare well under hard use.
To me, the 1911 frame in aluminum can't outlast its steel counterpart because the barrel link is attached to the slide stop through the aluminum hole in the frame...and that's where the "up & down" movement happens.
Egging or even cracking would show at that point.
Of course it don't happen overnight, don't panic.
P-38 frames made in aluminum failed until they added a steel reinforcement...and the feed ramp was pecked away by bullet tips upon chambering.
Ruger makes an all "plastic" frame and it holds up well and thats with no metal in the rails.