I've been using the mercer millennia 10 inch bread knife. One of the sharpest knives out of the box I've ever purchased, retained the edge well so far. It flies through absolutely everything I've thrown at it, functions great as a general purpose serrated knife.
Ultimately a bread knife isn't a chef's knife. I probably won't have it for the rest of my life, due to the difficulty in sharpening serrations. As such I have no interest in spending serious money on them, and see them the same way I see paring knives. They're disposable tools, and since the usage cases are much more time infrequent then chef's knives they don't justify spending serious money when a cheap one will do. Case in point is that mercer, it's $14 from Bezosbuy, and will likely perform at the same level as the super slicer or any other $100+ bread knife. Even if you work in a bakery there's no reason to spend significant cash on an expensive bread knife unless you're proficient in sharpening serrations, you're better off amortizing the cost by buying a new cheap bread knife as needed. Saves money, yields better results.
As such blade steel is irrelvant to me. Would it be great to have a serrated knife out of S110V so I can swoon over the effect of the carbide microserrations and their violent impact on bread crust even after the knife is dull? Sure. Is it worth spending the 10-20x the price of the mercer? Nope. So long as the knife comes sharp and isn't made of tin it'll probably be fine.
Only real thing I can think of being nice to have would be scallop serrations to not shred the crumb of a fresh baguette. Think Jay Fishers theater curtain serrations which are absolutely beautiful to look at, and I would think would perform quite well at not butchering a loaf. But again, is it worth multiple times the price of the Mercer? I would say not.