I dredged up my old 300R thread and found the manual camera settings, so here are beamshots.
Right-click the ones you're interested in and
open each one in a new browser tab, then switch from tab to tab for comparisons.
Planet Bike BRT5
NiteRider Cherry Bomb
Planet Bike SuperFlash
PDW Radbot 1000
DiNotte 140 on HIGH
DiNotte 300R on HIGH
NiteFlux RedZone4 on HIGH (note that it puts out 60 lumens in steady HIGH as shown here, but 200 lumens in flashing HIGH)
Cygolite Hotshot on MAX
Nova BULL powered by a DiNotte Li-ion battery pack. This is a weatherproof emergency-vehicle mini-strobe, about 120 lumens for the red model, and runs well on 9.6-15 volts. It's not made for bikes, so mounting it required creativity.
Ultrafire WF-501B flashlight with native red LED (does not have a flash mode).
The photos were taken at f8.0, 3.2 seconds exposure, ISO 50, auto white balance. The lights were running in steady-burn mode to allow general intensity comparisons. Distance to the wall is about 6 meters.
My opinion is that the Hotshot is currently the value winner, at about US$35 on Amazon.com,
provided it is carefully aimed. Small, lightweight, cheap, fairly powerful, adjustable, and good runtimes + rechargable.
I think the RZ4's best role is as a super-wide-angle light for use on a bag or helmet, where you can't aim it precisely. At night, it should have enough power for just about any scenario, but I don't think it has enough raw intensity to nail 'em to the wall in broad daylight at long range. For that, I'd go with the Hotshot, DiNotte 140 or 300R.