Why Amagi may have made the better carrier conversion

Would Amagi have been more useful as an aircraft carrier than Akagi?

Yes; Amagi likely would have made the better carrier if earthquake damage had not ended the conversion.

The exchange separates respect for Akagi and her crew from the underlying design counterfactual. Amagi was the battlecruiser hull originally selected for carrier conversion, but damage from the Great Kanto earthquake ended that plan. Akagi consequently took her place in the conversion program. Had the earthquake not intervened, Amagi would likely have produced the more useful aircraft carrier.