It improves the resistance to chipout on everything, carbon, A2, M2. Steve Elliot did a project about 10 years ago or something where he examined the final angle that A2 was optimized, and his sample, it was 32 degrees, I think. That's about where edge longevity and clearance will be maximized as a combination (i.e., maximum clearance while still not chipping out).
If you finish with a smoother (and no sanding and no scraping), chipout avoidance is important. I don't do it on any of my other planes, though, either, I just don't care to take the time to put an iron in a guide.
The couple of times I've tested irons against each other, when they were similar types, the one that chipped out first always lasted the least. It takes forever to do a realistic test on an iron in wood if you sharpen it properly, though, so I did that only a couple of times. It doesn't make sense to do that kind of stuff unless you're looking for a specific answer.
If you have to do something big where you have to finish both sides of panels, though, you get plenty of time working the good faces of a panel to tell which irons last longer.
Anyway, though, an properly cambered iron that fails only by wear and not chipping is an awfully nice thing to have in a smoothing plane. Zip two passes across a panel to finish plane it and done.