Good comparison. Whelen for the win....I did a comparison of some different lights a while back. Not sure if it qualifies as nice, but pretty thorough.
Whelen Freedom bar, Strobesmore EFLOOD 4200 warning series on dash, Whelen 600 grille lights, and Extreme Tactical Dynamics dash light.
https://www.youtube.com/watch?v=WqiI-W_HCtM