Originally Posted by
rfomenko
It's as bright as two Superflashes plus Radbot 1000 rolled into one. I have all of them & checked it out. Also, it has a reflector built in which the Superflash and Mars do not have. Radbot has one of course but it makes it twice as large as Cygolite while being half as powerful & almost as expensive. Also, Radbot's puny AAAs do not last more than 12 hours if you are lucky whereas Cygolite claims 28-29 hours. I am thinking about getting another one for my helmet. Finally, my search for a good inexpensive daytime taillight is over 
I've owned three Cygolites in my time, from a cheap Metro, a Expilion 350, to a MityCross 480 and their battery run time estimates have been spot on, unlike the Blackburn Mars 4 where the run time estimates were off by around 90%! Even Radbot run times are estimated at 30 hours which puts them off by 60%. Obviously neither Blackburn or Radbot ever tested their battery run times.