That was 2007. It's 2012, and things have changed. LED's are smaller, brighter, more efficient, and easily accessible. So I decided to venture out and look for a new rear blinky to

My only wishlist item for the Red Zone 4 would be a quick-release clamp for seatpost, as the velcro straps make it a bit cumbersome to remove. Lucky for me, I take my seat with me wherever I go, so the light stays on it, but I'd prefer a nice custom post clamp that the light could clip into and out of easily.
I've used the light for long enough to feel comfortable commenting on its performance. First and foremost, it's more noticeable than any other rear bike light I've ever seen, and programmable so you're not selecting a brightness that's blinding your fellow cyclists. I have mine programmed with just two strobe levels: 1.2 Wat & 4 Watt. I use the 1.2 Watt for normal nighttime riding, as it's the perfect balance of bright-but-not-too-bright. The 4 Watt strobe is great for daytime riding or really bad condition nighttime riding (like last night's snowstorm), where you want to be visible to everything and everyone. The battery lasts a long time between charges - to the point that I plug it in maybe once a month just because I feel like it, and not because it needs it.
NiteFlux also has amazing customer service - despite being on the other side of the world, they always promptly answered my questions, and give their products one year warranties with the ability to add on two more years for only a few more bucks.
I literally could go on and on about why I love this light, but suffice to say that if you're in the need of a rear bike light upgrade, the Red Zone 4 is your light - a hundred bucks is a tiny price to pay to keep yourself from getting hit by a car.