The FSA OS 115 Ti has just had a facelift to make it more sleek and in the process move to a flip flop +/- 6 degree format over the old, zero degree model.
This helps get the bars in the right spot (we flip ours to negative). At 138g it sits right in the sweetspot for modern lightweight stems that can be trusted in XC applications from short races to marathons.
The OS115 is also commonly found specced on high end road racing bikes, so you know that it's pretty light if the roadies like it. The light weight is thanks to some exceptional forging and machine work to sculpt thin, accurate wall thicknesses, a carbon face plate and six deep, domed-head titanium 4mm fasteners. With a 600mm bar with bar ends on and the rider in full leverage mode there's no movement that we'd call unreasonable.
Remember, while we don't condone noodle stems, too stiff a stem can make a short travel XC rig feel unnecessarily harsh. We liked this stem the first time, now we're in love.