Yeah, the material certainly isn't the only (or dominant) factor in sound. Profile makes a huge difference and thickness matters too. Still, to my ears, PBT tends to sound a bit more dull and ABS a bit more bright, but perhaps I'm imagining it.

I may also be imagining this, but to me ABS is effectively odorless while PBT has some kind of smell to it. By that "test", these are ABS, but ¯\_(ツ)_/¯