If riser bars aren't your thing, you'll be glad to know that 3T still makes some fantastically light flat bars. The 3T Xida LTD Carbon Handlebar is their top-shelf offering. It's made of high modulus unidirectional carbon fiber for an optimum strength to weight ratio. It's their lightest mountain handlebar, but it's perhaps most notable for a 3T design revolution -- a reduced width for the oversize center section of the bar. The engineers at 3T call it compact design.
What the 3T "compact" design does for you is allow a significantly greater clamping area for width adjustments for your cockpit controls with room to spare for fork lockouts, seatpost remote levers, and lighting systems. Their engineers reduced the width of the oversize center-section of the bar without sacrificing strength or stiffness. It doesn't even matter if you like a narrower bar and cut it down to their minimum recommended width of 570mm, you'll still have all the mounting freedom you could ask for.
The 3T Xida LTD Carbon Handlebar comes with a clearcoated unidirectional carbon fiber finish with silver graphics and is 640mm (25-3/16") wide. It's a flat bar, though the outer handles are offset by 3mm above the center of the 31.8mm clamping portion of the bar. It has a 3.5 degree sweep, half that of the Eryx riser bar series. The clamp surface is textured for a no-slip fit inside your stem.