Dinotte has a sub machine gun style flash mode which really catches attention. I find it is alot brighter then the superflashes and can be seen very well in the rain and during daylight. The extra lumens help lightup everything around you to the rear aiding in all around visibility. I had an old trailer LED tail light that tractor trailers/busses have but carting around that 12V battery and huge light was a pain.

As grun suggested I actually use both though. 2 Superflashes and a dinotte. For me though the superflashes are backup, and cheaper then a 2nd dinotte. I always have a backup light especially in the rear! You can easily tell if your front light goes out. Of course with 3 mirrors (2 bar ends and a eyeglass one) I can easily see my lights drowning the whole area behind me in red.