Recently, I needed to calibrate a shops wideband to determine if it was reading properly because the reading it was showing was leaner than I was showing on my widebands. No offical under the best conditional, but off the cuff test for my curiousity.
So to make a long story short, and although not the best application for testing, I had a little extra down time between tunes so it was time to play on my partners C6.
I plugged them all into one exhaust with seperate tail clamps while dynoing my partners C6
The NGK provided the fastest reading in either directions with more stability. Great unit for $250 buck, but the sensor cost around $150s to replace.
The LM1 provided about the same AFR number, but slightly longer to reach the numbers that the NGK reached. good unit. $250 bucks and about $50 bucks per sensor which seem to last me about three months it best.
Friends FAST under read (richer) than the LM1 and NGK. Not mine so I dont know cost.
Shops dyno jet crapped out from a loose wire just by chance and a replacement sensor was ordered, but in the past had read leaner than my LM1which was pretty much inline with the NGK, but slightly slower to respond.
So my experience was NGK won hands down with better reaction time and stability through the runs.
The LM1 which uses the same 3737 sensor as the LC1, not a bad unit but lost to the NGK hand down.
I had a LM2 and hated it. Sold it and bought the NGK.