The PlanetBike SuperFlash is the gold standard of blinkie rear lights. I liked mine just fine, but I also had my Cateye reflector-light break and wanted to try the PlanetBike alternative. And my general rule is that I don't like to have two lights from the same brand backing each other up.
The main thing that the NightRider Cherry Bomb brings to the table is a little bit of reflector power. They make it sound like a big thing, but I look at it and see something that is significantly dimmer than a CPSC reflector and the Cateye and Planet Bike lights that do contain a reflector. I wouldn't feel comfortable (and you know I'm obsessive) with having this light as my only rear-facing device under any circumstances.
One complaint is that takes two AAA batteries instead of AA batteries. AA batteries would give it a longer battery life and also mean that I could only keep AA spares. But the only light in the product space that does that is the Princeton Tec Swerve.