I use the Carbon Express Launch Pads and love them, never had a problem. I used the Nocturnals for 2 years and had a lot of problems with them. When I would hit something hard with the arrow (either a bone in the deer or the ground after pass thru) the batteries would blow out of the nock and slide down inside the arrow. This happen many times to me maybe 5 or more times.
Which one is the brightest ? Nockturnals, Lumenocks and the other brands posted in this thread ? When I made the two using the Thill Bobber lights, I drilled a hole in the end of the nock to let more light shine through the back. Here's a YouTube showing how to make one, and he drilled a hole in the nock too so it would be brighter. http://www.youtube.com/watch?v=hMqLT-4ezzk
Here is a link to the comparison that Justin Zarr did during the summer : http://forums.bowhunting.com/equipment-reviews/37423-lighted-nock-review.html. I also looked at doing the Thill bobber lights but decided for the price and time, I'd just buy Lumenocks.
I have been using tail lite nocks from tgbarchery They are extremely bright and all mine have worked every shot. They are about 5-6 bucks a nock
Tried the CX Launchpads this year. Failed to light on my buck shot. Sent them an email, got no reply. Will try something else next year.