sch3746636 wrote an answer about Light & Motion Vis 180 Tail Light on December 5, 2013
OK, so you're going to get two answers for evaluation, and for mine, I will say that I've never used any L&M light (I came across your inquiry while looking at an L&M taillight).
I have a Lupine Wilma which is accurately rated at 2800 lumens. Yes, 2800!!! At its highest setting (I have four settings programmed in, each significantly brighter than the last, with the fourth setting being full-on). I'll just say that I have no problem seeing ANYTHING on the road, even if I'm descending at 45+ mph. Was it expensive? Yes, but one crash would make what I paid inconsequential (and I know first hand - $25K later after a (daytime) accident of mine, and a subsequent collarbone surgery, a Lupine is a drop in the bucket... thankfully, I have insurance which covered 80%).
I also commute in Southern California (south Orange County), so being seen by the many motorists I encounter is a high-priority... I've had drivers in front of me "flash" me with their high-beams because they're getting hit with so much light.
Crazy thing is the Wilma is not Lupine's brightest - that goes to the Betty (got to love their names) which comes in at 3600 lumens. Yikes.
Now back to checking out L&M taillights here on the wonderful Competitive Cyclist (kudos to them for allowing the posting of info about stuff they don't sell... they're a great company). I hope my input helps you, and others.