I have always felt you need to look at the connecting rods as a "system". The rods, the piston weight, fasteners and the machining accuracy Each of these components can make or break the "system". That's why some of us have had luck racing inferior parts, like myself without "system failure". In the 1980's. I ran the rubber rods, with lighter than stock pistons, superior fasteners, and perfect machining and balance at 6000-6200 RPM for hundreds of runs without a rod failure in a 421 in NMCA stock class. Lucky?, Probably. But that was the best available to those of us without a huge budget. Building an engine today, on a budget, I would use the best off shore aftermarket rod I could afford. Probably Molnar. If using Eagle or a no-name generic Chinese rod, the quality of the machining process becomes much more important to the "system". Every dimension needs to be verified and even today, every Eagle set of 8 rods I see need at least some re-machining to the big or small ends for size, out of round or taper. Just part of the build process. At the RPM range most of our Pontiac street engines run, connecting rod material and forged vs cast is a much less important part of the "system" than the quality of the finished machined part.
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