Opinion:
Aluminum Rods - It has been noted that some of the aftermarket steel rods have failed. I've run Crowers and Carillos. And I pulled them out and measured them afterwards. .0002" change max, which is about normal for anything that has been heat cycled even without load. So my problem with bending rods is solved for now.
There might be some gain from reducing mass, it's a question of how much gain, and how much money. We all have a "budget", and we try to focus on mods that get max Bang For Dee Buck.
Because of that, with my personal budget, aluminum rods aren't in my future unless they are significantly cheaper than steel, and at least as strong.
But this might not apply to everyone. I try to go fast by figuring out what is slowing me down, then fixing that. For me at least, steel rods aren't my problem.