When I was looking for bike lights I came across several that were much more powerful than this one, however I was a bit wary about having a light so powerful that it would be distracting/blinding to drivers.
Which is why I chose this light. It is perfect if you need something that is more powerful than the standard lights you get in a pack/with the bike, but not so bright it will distract drivers if they stop behind you.
I cycle through a road at night sometimes, and it's pretty much pitch black at certain parts, as well as being downhill, so I needed a bike light that was more powerful than my current light. This one works really well, when I look behind I can actually see it flashing behind me, and I'm sure other cars can as well.
It's easy to attach and remove, although sometimes it can accidentally be switched on if you it gets moved around in your bag. Other than that I would definitely recommend it to others looking for a decent rear light.