For example, it is more akin to a cylinder and a torus. There are big benefits here: I can definitely eat faster from one end to another in a straight line instead of eating in a circle. And you can avoid that messy first bite where you have to break the loop.
Also, an eclair has cream filling instead of a gaping hole. That delicious cream filling really set's an eclair apart from a simple donut in my eyes.
It is interesting how aptly named the Android releases have been. Cupcake was a good choice for a first time baker. You can learn alot about how to mix ingredients and add toppings. A donut is a bit of a twist with some added complications - primarily caused by that often misunderstood shape. And then there is eclair: it is all stretched out and filled in. No more gaps. Quite simply it is a donut evolved.
Especially in the eyes of an audio engineer. I am going to have fun playing with all the creamy filling in eclair.