depends on what you want to do with them. The LM lights are literally the front of a princeton tec with a delrin machined back end. If you're spending that much on lights, then these are brighter, use 18650's, and have the battery level indicator on the button
Cave Adventurers - Explorer back-up lights - Marianna, Florida USA - Never Undersold!
they are real slick lights, and I have mine bungeed to my helmet. The mounts are slick though and if you intend on removing them from the helmet regularly may be the better option. Mine is for cave diving, so they come off after every dive to change batteries since I use the video heads for my gopro, but they don't come off in the water.
SecurityIng Waterproof 1000Lm XM-L2 U2-1A LED IP68 Diving Flashlight 250M Lighting Distance Maximum 150 Meters Underwater Distance with Magnetic Switch (Without Battery) - - Amazon.com
I use these as my backup lights, but they don't come with batteries or a charger. I think this is actually a good thing because the batteries and chargers you can get are much better, i.e. panasonic cells instead of cheap chinese batteries and multi slot chargers.
Amazon.com: NiteCore-D4+CAR-Adapter+BBOX-T Bundle Nitecore D4 Charger Integrated LCD Panel Display for Li-Ion Ni-MH Ni-Cd Batteries with EASTSHINE Car Adapter and EASTSHINE Battery Box: Electronics
3400mAh TWO 18650 PROTECTED Panasonic 18650 Rechargeable Battery - High Performance - 3.7 Volt - Dual Protection For High Performance Flashlights - - Amazon.com
So you're looking at $200 for the rats, or $170 ish for the ones listed from amazon, but with that you have 4 18650's with legit panasonic cells, and a much better/brighter light if you're using them for primaries with a higher quality charger. The rats are still stupid simple reliable backup lights for caves and what not, but less than ideal for regular use. I do prefer the amazon lights to the CA's for helmet mount because the rear button push is easier than the head switch, but we're really splitting hairs. I do have a pair of the CA's in video spread and if you want the wide angle for that or gauge readers in sidemount, they are really slick