My favorite do-it-all, lightweight shell
Almost every major outdoor apparel brand makes a lightweight, waterproof shell. I’ve used a lot of them, but the Strafe Scout jacket is my hands-down favorite.
The fit and material choices are what make it stand out. Strafes uses a thin but bomber 2.5-layer proprietary waterproof breathable fabric with built-in four-way stretch, and then gives the jacket an athletic cut, so it's svelte and efficient but still allows for plenty of movement on high-alpine scrambles or while hunched over your bike. Although, because it’s a unisex piece, I suggest men size up.
The Scout is lighter than both the 7Mesh Revelation and Outdoor Research Helium II—two other great options in the category—and stuffs into the singe chest pocket like the non-waterproof Patagonia Houdini.
For features, what you see is what you get. The elastic hood stays put, and a little elastic in the waistband helps the jacket fit comfortably over tiny running shorts or mountain bike baggies. That chest pocket holds a phone or bar, and protects the membrane from dirt and oil when the jacket is stuffed inside.
Like all waterproof/breathable products, the Scout has its limitations. After 10 minutes of hiking or mountain biking uphill during a rainstorm, the inside gets clammy. But that's true of any waterproof layer, and I can confidently say the Scott breathes better than other, burlier, three-layer shells, which are overkill on all but the most extreme summer missions.