Wouldn't call it a monstrous resonator, but you're right, I didn't consider the resonator.
I had a non-resonated "N1" stile exhaust with a cat delete on my Mazda3 ten years ago. Thing was loud, but with that particular car, not as loud as the above configuration. Different car, of course. Also depends on who makes the system. "N1" stile mufflers are not all created equally.