Joined: Jul 2002
Posts: 40,863
Likes: 3,116
From: Sacramento, California, USA
Bikes: Specialized Tarmac, Canyon Exceed, Specialized Transition, Ellsworth Roots, Ridley Excalibur
Watts are watts. Physiologically, an equivalent power output will be equivalently draining. And that's why power meters are useful training tools.
Psychologically though, it can vary.