In the first, I used to have regular looking aerobars on my full rigid Kona MTB that I used to use as a commuter and for century rides, even did one double century on it. With the aerobars I was only about 5 minutes off the lead pack after 100 miles and about 8000 vertical on one ride. I'd catch up on the climbs then get passed on the downhill and I didn't lose much time on the flats, but I was spinning the big chainring like a madman!
In the second, I had some aerobars similar to the ones in the previous post on my MTB. It was way back in '02 when I was getting ready for my first La Ruta. I had read that there was very long flat section on the last day. I wanted to be prepared for anything and everything because there was no way that I was going down there and being one of the folks that DNFed. I found them at Performance. The arms were more curved, looked a little like horseshoes. They were lighter than regular aerobars so I got 'em before heading out to New Mexico to get in some final training before leaving for Costa Rica. I grew up in NM. There's a volcano, Mt Taylor, with a summit at 11,000 feet and I though it would be similar to the Irazul volcano we'd have to climb on day two. There was also a 40 mile relatively flat loop that I used to time myself on. I absolutely SMASHED my previous time with the aerobars on. Fast forward to La Ruta day 3 in 2002. That year and in 2003 there was a long 10 mile flat section (veterans: not the first one after CP2, the one right before the first set of train tracks. I'm talking about the second one that was pretty much taken out in '04). When I got there I got in my Chris Boardman tuck position and started reeling in the tiny dots in the distance. When I'd catch up I'd ask if they wanted a pull. Of course they could only hang on for a couple of minutes. It was insane. Those were the only two times I ever used the MTB aerobars. They weren't useful at all on the first two days and I shouldn't have even had them on.
The main reason I didn't use them after that was because in '03 almost every race I did was new to me so I didn't really know much about the course and I didn't want to have any extra weight. In '04 I got into the 24-hour solo thing and there's no use for them there. Now that I know more courses, know alot of racers that have raced all over and can use web forums where a rider can get good information on a race course, I might actually use them again. Any course that has at least a 10 mile flat section is a good candidate so Brianhead would be good. It would be awesome for the Soul Ride course. They wouldn't have helped me last year at the Soul Ride though...having 7 freaking flats tends to slow a rider down, but that's a different story.