The 18.5 cm length hits a sweet spot for me, and the curved shape actually reaches where I want it to. The jelly material has just enough give without feeling flimsy, and the prominent head adds a nice bit of realism.
The size caught me off guard at first, but the jelly material has just enough give that it warms up quickly and feels way less rigid than I expected. The curved shape hits the right spot without much effort on my part.