gilipollas wrote a review of Exposure Trace Light Pack on April 15, 2014
Familiarity: I've put it through the wringer
These little lights are pricey, but worth it in my opinion, especially on sale (they are currently).
At first, I was taken by the fact that these are small and aluminum. Lots of other lights are huge, plastic, and ugly. I commute on a single speed, and I don't need a huge light with 500 lumens, and I need the lights to be small so I can remove them quickly when I lock my bike and put them in a backpack pocket easily. These did the trick.
They're nice looking, small, and feel really high quality. Operation is a bit tricky, don't throw out the instruction manual, but once you get it, it's easy enough. 6 settings (constant and strobe at 3 different brightness levels), but the middle and low settings are enough for me. The bright one is ridiculous, I can see the reflective layer on street signs a quarter mile down the road when it's on bright.
They're waterproof and shockproof, I've dropped them a few times and they still work. They charge with included USB cables (2) and have mounts for front handlebar and rear seatpost. I purchased the under-the-saddle mount from a seller on ebay as I couldn't find it anywhere in the US, and that's also a nice product (if you care about a lot of things hanging off your bike and cluttering it, like I do).
I would equate these to the iPhone of simple bike lights. They don't offer any incredible functionality over cheaper lights, but they do what they do reliably and in a sexy package made of top-of-the-line materials.