Here's the side-by-side, as promised. The jug on the left got no whirlfloc and formed a nice compact trub. The jug on the right got whirlfloc and is pretty fluffy. Everything else was identical, except for the type of hops. These were all extract batches, fermented for 14 days, plus 14 additional days with 1/2 oz of pellet dry hops using WY1968. Every other batch that got whirlfloc had the same chunky trub.
These batches are still bottle conditioning, so I'm not sure if there will be any clarity difference in the final beer. I'll pour these two side by side once they're carbed up to see if there's any appreciable difference.