FSA's Carbon faced XC unit gets a distinctive contrasting shot-peened and smooth CNC design with various flutes, flanges, drillings and cutaways to shave off grams. Each length is butted differently too so while it does flex it's not nearly as noodley as some stems.
The fat carbon front plate keeps a firm hold on proceedings and its still relatively smooth and knee friendly at the back end. Thread prepped Ti bolts minimise weight but a new lighter OS99 alloy faced stem has just been announced. There's a wide range of sizes and angles plus flip flop decals but the high price means you'll have to invert your piggy bank too.