I too used both LD1000 and Superflash. They were both the same price at Nasbar ($25 each, free shipping). I got both of them after reading tons of reviews in this forum and CPF. I mounted both of them on my seat post, the superflash on top and LD1000 right below.

To be honest I can't which one is better, though the SF is brighter a bit. I think the key point of the SF is also the unique flashing mode, not just its brightness. Now when I run at night I turn 1 line out of 2 from LD1000 on as others suggested in this forum (for cars to judge the distance) and use SF as blinky. The result was excellent, some cars even drive to the other lane to avoid me. And I live in Brooklyn, a city that is famous for reckless driving.

$50 is well worth spend, replacing my old Vistalite taillight, which is less than half price of the dinotte one.