I had tried a few handlebar bags. The large ones came with a superstructure of struts and braces that extended to the front wheel. Some sat trunk-like on a front wheel rack, well below the handlebars. Others had no internal dividers which meant that cameras and phones--and snacks--were free to beat on each other during a ride. The smallest ones simply hung from the handlebars by straps and flapped freely while I rode. I couldn't see trusting my Canon S95 and iPhone to a flapping case with no dividers.
The Detours Metro F is exactly what I've been looking for in a handlebar bag. It mounts in seconds to a simple handlebar clip and comes with two carefully thought out compartments, each of which has padded compartments that fit snugly around both my camera and phone. Inside, I found a rain cover that was able to protect the whole bag in seconds. This is a nicely designed little bag with excellent ergonomics throughout!
One quibble, the red graphic doesn't go with my bike, nor would the alternative blue. But the bag itself is such a pleasure to use that I simply leave it in place for all my rides. Unlike many of the bags I've tried, The Detours Metro does not effect my bike's handling.
The same clip that hold the Metro in place also supports a much larger bag, the City, shown here with just a jacket inside. I daresay you could fit a LOT more stuff in a City. This would be the bag for weekend trips. Swapping bags requires no tools and takes less than one minute.
If even the City, bulges at the seams— say, you plan on hauling firewood, whiskey and a set of pipe wrenches on a trip to Patagonia—you'll want to join the struts and front rack crowd. However, if you actually are heading for Patagonia—you do need to ask yourself this question: am I still having fun riding this bike?
I'm in it for the fun so I'll stick with the Metro F for most rides and add the City for light touring.