The stickers arrived today and I've been working on putting them on the keyboard.
Early impressions: There were no stickers for keys like Enter, Shift, Backspace, etc. I guess they figured users know where those keys are by default? A surprise, but not a deal breaker.
Because of the way the Mini 9 keyboard is laid out (I have the US, not US-Int'l keyboard), I've had to trim several stickers so that the alternate image is still visible.
I turned off the lights to see how they looked, and was immediately able to tell which keys had the stickers and which didn't (I'm still working on the home line due to the trimming). I'm not sure if they "glow" necessarily, but they do make the letters/numbers more visible.
Another plus: If you do a good job installing (using their applicator helps), it's hard to tell even close up that these are stickers on the keys. That was one thing I didn't like about the ones that were shown in the photographs on the first page: it was obvious there was a product on the keyboard.
I've attached two poor quality images from my (crappy) cell phone. One is off the stickers as they came out of the package, another is a closeup of the first few keys applied. If I can find my good camera, I'll try and take more (and better!) photos.
Anyways, for the TL : DR crowd...I'd recommend these stickers.