Most lighted nocks are all going to weight from 18-25 grains. So far I have tried Nocturnals, Glocy Nocks, Lumenocks, Firenocks, cheap ebay ones made by people here in the US, and a few others I can't think of.
Nocturnals I tried for two seasons. Each year was a different package of nocks and each year I generally harvest about 6-8 animals during archery season. The first season I used them I had 4 out of the 6 deer I shot go off after passing through the animal. I could see them light up fine but the moment they went through the animal and stuck in the ground they would turn off. The second year I shot either 8 or 9 deer and I had 5 do the same thing. I also hated the way these would turn off.
Glory nocks I haven't tested them on animals but I have shot them into a lot of hard objects to see if they would turn off. I have not had one turn off, it seems like a fail proof system that is very easy to turn off. The only thing I do not like is the size of the nock. You might have to open up your D-Loop a little to accommodate the nock.
Lumenocks I would have turn off while shooting. I think it was the way the nock was fitted but I can't give you a 100% honest review on them but if you buy the lumenocks get the HD orange. They are probably brighter than any nock I have seen.
Firenocks are pricey but so far they have been my favorite. The nocks are high quality, very bright, and I have not have one shut off on game, you can also replace batteries like the lumenock. Also Firenocks offer a practice set so you do not have to keep shooting the lighted nocks.
Ebay ones were straight crap.
In regards to battery life Firenock wins hands down. I have over 30 days with a firenock on, both nockturnal and Glory Nock were roughly 40 hours, and the Lumenock I never tested that one but it wouldn't surprise me if they were at least 40 hours.
If you have the money I say Firenocks, if not I would probably buy Lumenocks or Glory Nocks.