Bike fit / correct riding position

I'm somewhat curious as to the use of clip on aero extensions for long rides. I dont think I'll see an overall speed improvement from teh aeros as such. I was more interested in pure endurance, and prehaps a more comfy aero position would get used more. Giving a net gain.

You will gain from aerodynamics and you will gain from not having to use your upper body to support yourself. For long, solo rides, they're great. Braking and being nimble through any kind of town or traffic is not so good.

Ride near roadie types in a bunch though and expect to be left on the front or dropped and left for dead :)