Without using up any energy? I believe that`s what 2W was getting at.

Just as on an upright, you the rider can control how hard you ride. You can ride your 'bent the same speed using less energy or you can ride faster or farther using the same energy. Or you can ride *much* faster using more energy. From my point of view, being more aerodynamic means I get more return, in the form of speed, for the energy I'm expending; and the more I expend the better return I get. Therefore I'm encouraged to expend as much as I can.

Regarding upper body use, I never realized how much energy it took to hold the upper body in such an unnatural position until I got my first 'bent and didn't have to anymore. The core muscles are designed to hold the body erect, not bent over at a 45 degree angle.

Yep. That's what I was getting at.

Muscles are used to keep oneself in position on an upright bike, whether arms or core. Muscle use means work done and, over time, exertion.

So is your contention then that one "advantage" of a recumbent is Less Exertion for Equivalent Speed when compared to a DF?
(I'm not necessarily disagreeing, just don't think I've ever heard that argument put forward before.)

I think the contention is, on a longer ride the upper body strain of an upright has an additional 'wearing' effect. Without it, the recumbent rider will tend to feel less beat-up at the end of a ride. With it, the rider may wear out a little bit sooner. The difference in exertion isn't going to translate directly into a speed increase/decrease. Most recumbenteurs will agree that the difference in aerodynamics and overall comfort make the biggest difference in how far or fast they can ride.

The lack of "wear" and strain on the upper body was in great evidence when I first started riding bents 6 years ago. On my first rides on my first bent, I rode my usual route. I was amazed at how much less tired I was when I got home on the bent. It left me wishing I had taken a longer route. Of course I did pick out longer routes, and as I have posted before, I ride futher faster and longer on the bent.

Sorry, I know it's usually bad form to quote oneself. But I wanted to amplify on this.

Since an upright rider only knows riding uprights, that's their standard for measurement. So, to them, there's not an issue. It's not really accurate to say they'll wear out faster, even though from our perspective that's the case. Like a audiophile who has never heard stereo, they don't recognize the problem. (It's all high-fidelity sound, right?) By contrast, most recumbent riders started on uprights and moved to recumbents. So, with experience, the difference is obvious to us. (Whoa! The guitar is coming from the right, just like it was on the stage!)

blazing pedals +1

The bottom line for bents come in several parts. 1) comfort is a given 2) the fact that "on board energy" is mainly fed to the legs and not the upper body 3) aerodynamics is a variable given depending on bent design--and it is true that it is mainly important above 15mph, but dont forget if you are riding even just 10mph into a 15mph wind now we are talking 25mph relative wind speed so bent aero is important 4) riding experience many besides myself noticed on our first bent rides that we were less tired when we rode the same routes we had been riding on our DFs 5) and lastly since 99%+ bent riders had ridden thousands of miles on DFs before we got bent we are the expierenced judges of both types-----we are not just repeating old wives tails and hearsay about bents but have never ridden one

DF forums speak of their bikes, accessories and accomplishments.
Recumbent forums speak of comparisons to DF's, energy considerations as compared to DF's and the great wisdom of recumbent riders as compared to DF riders.
And if you say you like both for different reasons then there really must be something wrong with you........and plenty of recumbent riders to tell you what!

BTW

When Rans entered their 4 man team in RAAM, they exploded the myth that bents dont climb. Not only did they win their catagory, but while in the mountains in the west they increased their lead riding up the western side of the Rockies.

Lets talk pain. Riding in pain is just plain stupid. The DF crowd will state that if your DF has "proper fit" you will have no pain. What a load of ****. In that case no one in the bike clubs or tours have the "proper fit"!!! I watch at a sag stop and watch the DF riders immediately jump off their bikes and shake out their hands and start pulling at their laundry. Bent riders do none of this. If world class racers want or need to be in pain so be it. But for the average joe or jill riding for fun and fitness they are far better served if they ride a bent. All other real or imagined pros and cons of a DF vs Bent aside---riding in pain is just plain stupid. And especially for longer distances bents are naturally comfortable.