I'm not a fan of lightweight at any cost. I like the Ti whistle because even though I "know" I'll never need it, it carries easy so I carry it regardless. That said, the Ti whistle is a back-up. The whistles I keep in my backpacks are Fox 40 Sharx. I like the form and they are plenty loud. At least for me, the Sharx blows much easier than the Fox 40 Micro. I'd like to try a Fox 40 Sonik Blast, but for now, the Sharx is what I have in my kits.