When I ride my road bike, I do want to "relax" into the aero position. When I ride my triathlon bike, I don't ride aero ALL the time, because it's just not comfortable to sit in one position for hours on end. I do all of my interval work and mid-week rides as aero as possible, I climb hills as long in aero as I can, etc. For my long rides, I ride as much as I can aero, but it takes me several weeks to build up to more than 3 hours of aero riding. At first, 2 hours is about all I can take. During triathlons, the truth is that I ride aero as much as I can, but rarely is an event long and flat and perfect for riding aero ALL the time - there are hills, other riders, etc, even over multiple hours.

My road bike isn't as high-end as my triathlon bike, though, so I try not to make exact comparisons. I think I have adjusted to the geometry, but I could certainly adjust to riding a road bike, too. It's just weird sometimes to not have aero bars.