LEU Treehugger is being rebuilt. In the process, streamlined struts (not the large size, but one size down) were purchased from Carlson and installed. They look good, but we compared the weight with the original round alum tubing, and found them to be almost three times heavier. Seems the alum tubing struts were about 2 - 3 lbs, and the streamline struts were around 7 - 8 lbs each. Jury struts were installed, but the strut from forward spar to aft spar was left off (saved a few ounces?).
I know the Carlson struts will have lower drag compared to round, but, at the speeds this airplane flies, I don't see a pay-off. I think keeping weight down is the way to go. If this was my decision alone, I would go with round tubing and use some light-weight technique to streamline them. I'm not a primary player in the rebuild, so my vote did not count for too much!!!