I’ve been an aerobar fan for a long time. It dates back to my first set, which were the original John Tobin designed ones, which were probably the most comfortable and best designed to this day. Unfortunately, they seem to be permanently attached to one of my older bikes, and I haven't worked up the courage yet to try to extract them.
From there, I moved into my Scott bar period. They got down to a reasonable price point, and I bought a lifetime supply (truly, since unlike many other bike parts, they don't wear out). The one thing I didn't like about them was that they clamped on the handlebars far enough apart to interfere with putting your hands on the tops for climbing. I circumvented this by bending them somewhat extremely to move the arms in closer to the stem. One set I bent a little too vigorously, and ended up breaking them in half. So I lashed them back together with some used inner tubes and away I went. I dabbled with the famous Sark bar, which was a narrow affair that looked sort of like a tuning fork, and clamped somewhat precariously to the stem. I've got one mounted to this day, and another set in the wings that I picked up at the big event.
Somewhere along the lines, I discovered that you really didn't need those armrests, adding unnecessary weight, you could just suspend yourself in midair or if you got tired, lean on the handlebar itself. When I first tried this on the tandem, it felt a little shaky at first, but I soon got used to it. This encouraged me to even more daring aero designs. With my new bike, I have reached the zenith. Having spent a small fortune to get the lightest bike possible, I couldn't see heaping unnecessary ounces on the fine machine. I had the two pieces from the previous bar that had been rent in twain on my workbench, and as I regarded them, I cried "Eureka" (like that Greek fellow, not the vacuum cleaner). I had discovered the ultimate lightweight aerobar. I took one of the pieces, hack sawed the end and filed it nicely, then inserted a barend cap. Then I mounted it on the handlebar, and, voila, I had an aerobar of the unicorn variety. Using it took a little practice, my hand position looked someone in prayer, and you really couldn't squirm around too much in that position, but it basically worked. And now I've got the right hand arm to make another one!