Icon did very well. But, of course, they're also 10+ years late to the game and it's easy to copy various existing designs and tweak them to improve a bit. Which is what they've done. But yes, it's a solid choice.
As far as a 10% difference in anvil failure, this is statistically irrelevant. The reality is that you could buy the same steel type, from the same mill, monthly over one year, process it in the same facility, same equipment, same heat treat..... and easily get more than +/-10% if you did a statistical analysis on failure strength. And you could easily get a +/- 5% strength variance in the same batch of steel just due to heat treat variations. Variation in hardness produces variation in failure strength; and 5% isn't a lot of variation. These items are mass produced, and a bunch of small parts, like ratchet anvils, typically get thrown into a basket for heat treating. The parts at the outside of the basket will be harder, and stronger, than the parts at the center of the basket. Steel is produced to meet minimum standards. Sometimes it's much better. Sometimes it's a hair below the strength spec- I've rejected steel for critical designs at work due to independent tensile testing showing it's slightly below the minimum strength spec.
I'm not discounting that the Icon is a good ratchet, but just that a 10% difference in failure strength is irrelevant unless you test hundreds of products over hundreds of production runs over an extended time. And if you're using a 3/8 ratchet at even 200lbf-ft, you're well into where you should expect a failure as you're well into 1/2 drive territory.
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