Frankly: I am skeptical of all but the first tier of startup accelerators, and I am especially skeptical of startup accelerators based in Chicago, a locale not conducive to funding. One argument the post made that I'm confident is correct is that the accelerator model, when it ever makes sense, does so only when the company is on a trajectory towards raising funds.
I also find the idea that Excelerate charges more than YC to be jarring. It shouldn't be controversial to say that YC is the more impactful of the two programs.