Unfortunately I haven't yet come across a CR123-based headlamp that fits all my criteria as a backpacker and a hiker. I do a fair amount of hiking at night, so realize my needs may be a little different from yours, but I prize runtime, versatility, and usability in camp as well as on the trail. The Saint Minimus gets rather close, with an extremely balanced beam that looks rather floody but still has a bit of a punch to it, allowing you to see mid-distances pretty well but still get up close work done comfortably. But it doesn't have red output, which is something I really like having, the only ding on an otherwise phenomenal headlamp. I own a Zebralight H31Fw and I do like it but I find the Saint Minimus significantly better, since the H31 runs low on batteries without warning, and the beam is better balanced on the Saint for a wider variety of tasks.
So for me, two more traditional headlamps really stand out as matching my needs: Black Diamond Spot (or Storm) and Petzl Tikka XP2. Both run on AAA's unfortunately but AAA's are light (11.5g each) and both headlamps are quite compact as well as lightweight, maybe a little bigger than a golf ball. Both offer throw mode as well as a flood mode (the BD by switching LEDs and the Petzl by flipping up/down a diffuser), with the Petzl's flood being brighter and faster to access and the BD's being wider. Both also offer a red output mode, which I cannot stress enough on more social backpacking trips: red output has become the popular thing around here on the backpacking trails at night because it doesn't disturb other hikers who may be sleeping, allowing you to rummage through your stuff without bothering anyone. Where the BD and Petzl really differ, though, is that the BD can ramp down the output continuously, allowing you to pick precisely the amount of output you like (cool, but not something I use too often), and the Petzl supports an inline rechargeable, reprogrammable Li-ion battery pack (Petzl CORE).