1 Unicorn worker is roughly equivalent to a Thin instance. You can only put a single Thin instance on a dyno, meaning that the first benchmark is what you previously could only attain in terms of throughput.
I might've not explicitly said this in my article, but see the first benchmark where I say:
"1 Unicorn Worker (Roughly equivalent to a single Thin instance)" - stating that this is Thin's (and was Heroku's) previous limit.
With Unicorn you can gain 3 to 4 times more throughput.
