I can't attest to using the reds on a soprano, but my mom has an Oscar Schmidt OU3 concert and we've tried many different strings to find the right voice for that uke. We settled on the regular Aquilas, though it still wasn't quite right. Once the reds came out, I slapped a set of them on that uke, and those ARE the right strings for the uke. It really opened it up quite nicely. The uke sounds as one would think it would. That, and my mom loves the feel of those strings. The regular nylgut would hurt her fingers after 30-minutes of playing, but now she can play on the reds all day.
Dan