Reds are COMPLETELY different to Nylguts. I'm not at all a fan of Nylguts. I really like the Reds (at least, this far, on the Moonbird, and looking forward to trying them on the lutulele).I like the Aquila reds on my Kanilea tenor, which is suprising given my indifference to the Nylguts. Would like to see how the reds sound on my Koaloha tenor (the stock fluorocarbon strings sound so good, though).