I don't think I have seen this product mentioned here until referenced in a post I saw today.
http://www.reallite.com/RLHome.htm

Now this is a warranty!
http://www.reallite.com/warranty.htm

Is anyone using it?

Can you compare it to the Planetbike Superflash, Blackburn Mars 3.0, or Cateye LD610 or LD1100?

How about a comparison to the Dinotte taillight?

Hard to compare. This thing is huge. And 4AA's makes it pretty power hungry, even if for 60 hours. It would be interesting to see one of those You Tube comparisons for brightness vs. all of the lights you mentioned.

I used one for several years, but I've put it away now that I've got a Cataye TL-LD1000. I enjoyed having it, it's a big light but not nearly as bright as the more recent innovations. It performs as advertised, and the instruction manual is humorously written. http://www.thirdwave-websites.com/bike/night-bicycle-riding.cfm