L&M Repair
 

Just an update - L&M repaired my two Taz lights and they work great. They did let me know the recent lights have updated firmware that they loaded this update on mine. No root cause on failure, but I suspect their mentioning this indicated it was part of it. None of their single LED lights have failed me, only those with self contained battery + multiple LED in the head (sorry if I wrote this in a way that confused - only 2/4 of my bar mounted lights have failed). Online it looks like quite a few others had issues with Taz lights just stopping as well, but what I can say is that their customer service is amazing and their repair appears solid. I'm hoping the firmware update resolves all issues and they work both for me and for you if you bought the 2k lumen (I have 1200 and 1500). Still the best beam pattern for a handlebar mounted light by far. Happy riding!

That's weird
 

I have a L&M Taz 2000 purchased 3 months ago and, due to weather and other things, really hasn't gotten much use. So, when I got up this morning it was on. So, I pressed the on/off button to turn it off and the button blinks red 4 times, pauses, red 3 times, and the light goes off. Then, a moment later comes back on, on/off button is dark. Rinse and repeat. The light was inside, and I haven't used it for days, so can't imagine what triggered this. Contacting L&M, we'll see how it goes.

A follow-up to my previous post. Somehow water had gotten into my Taz, you could see condensation on the lens and side lights. It continued to cycle for a few more days as the battery died. I never was able to turn it off or get it to stop. L&M customer service recommended I put it in front of a fan as it may dry out. I did that and eventually the condensation did clear up, however at that point it was completely broken - the battery was dead and wouldn't take a charge, i.e. leaving it connected to a charger and nothing would happen, no matter how long it was connected.
But anyway, in terms of warranty, L&M credited me with the amount I paid for the TAZ to use on their web-site for a replacement or something else. Rather than another TAZ I opted for a Seca 2000 (which required adding an additional $30 to cover the additional cost), so that I could use on my helmet or handlebars. Customer service has been easy to work with, no complaints.

I was considering buying a Taz 1200 since the price is reasonable, but this thread confirms the same complaint several folks expressed on Amazon reviews and elsewhere: for whatever reason, the Taz lights seem sub-par, by Light & Motion standards, for battery life. Too many complaints of batteries failing after only a few months, and not holding a charge between uses.

Too bad. I was hoping to get a Taz for my nighttime rural rides, where a broader and brighter beam would be helpful.

But I'll probably get another Urban. My Urban 500 is going on more than 3 years and still works great, with about the same runtime per charge as when new. Some little nagging annoyances: the plastic USB port cap broke off, so I have to pull it off carefully; the rubber band strap broke, so I replaced it with a Two Fish which works great; and the light can't be charged and run simultaneously, which L&M fixed in the Rando model. But a 900 or more powerful Urban would do pretty well.

I love my urban 900👍🏽👍🏽

I see NiteRider has a new dual-LED model, the Lumina Dual 1800. I may get that instead. I've been pretty satisfied with my Lumina Micro 850. The mount and USB port cover are better than the Light & Motion Urban series. The NiteRider can be used while charging from a USB batery. Early reviews are good, and NiteRider has a good reputation for customer support.

The only weakness with my Lumina Micro 850 was one I already expected: short battery life. It's the small (hence "Micro") model, with a bright maximum output. It's really more of a commuter or errand light, smaller and very bright. But the maximum output is good for only a few minutes and it quickly decreases in brightness over the next hour, finally ending up around 200 lumens after about 90 minutes. It works best at medium output where the brightness is a bit more stable and it lasts longer. I suspect the 850 lumens is a sort of turbo boost mode.

But the larger NiteRiders appear to have good runtime per charge, according to the "We Test Lights" site operated by rival Light & Motion.