Yep. I am not sure they are legal in all western states yet. Colorado they are. As mentioned, it is easier to track arrow flight and easier to find your arrow, especially near dawn or dusk. During the daylight hours I don't use em for big game as it's usually it's pretty easy to find/track my arrow. I do use em on my "small game" arrows most the time but if/when you do lose one, just adds insult to injury as well as another 4-5$.
I used them for one hunt and pulled them out. Nothing against the knock, it was more where I was hunting and how.
I personally have an arrow nocked as I spot and stalk, many guys on here don't. My area is super thick and animal engagements happy quickly prior to the rut. So I keep it nocked only when in area I know holds elk. The round stem that sits in the arrow shaft is decent, but where it connects to the electrical part is a weak link. I bent one and didnt know it til ready to shoot. Seems my arrow got hooked on a branch and bent the nock at its weak spot.
I love the idea of them, and still use them in certain scenarios. My FOC is extremely high so the extra 18 grains isn't a big deal for me.
I believe the ones I was using are like 24 Grains, which is 3 times the weight of a normal nock.
I will be using them again this year in certain areas and with more caution and awareness
I shoot victory rips, they have an optional aluminum nock that weighs 15-17 grains I think. Either way, I run those for practice so when I use lighted nocks it's only a couple grains difference. I also shoot a 500 grain arrow and I think it makes less of a difference than on light arrows.