I found them to be significantly brighter but somewhat directional. By that I mean they appear brighter when viewed directly behind the vehicle but less so when to the side. Kind of like looking at an LCD monitor from the side.
Since the LEDs draw very little current, less voltage drop (loss) occurs in the wiring between coach and tail lights of the toad and they stay t full brightness.
Last year, In daylight,I was hailed on the CB by a Semi driver who advised me that my "blinkers" were barely visible and might cause a citation to be issued. That was in Ca or OR. That evening I found an auto store and purchased a pair of LED replacement bulbs. They are much easier to see in daylight.
Tried clear and red. Definitely go with the red for a red lens taillight.
2003 34' Dolphin 5342, W22, UP, UPGBrake, F and R Track Bars, Rear IPD sway bar, Koni FSDs, Safe-T-Plus, Scan Gauge II.. 2004 Jeep Liberty, Blue-Ox Adventa..