There is a review coming on these ignitors (and a soon to be released launch system). Here is a summary statement on the ignitors:
"Overall, I can recommend the Slim Gems for their intended purpose without reservations. The Fatboys are recommended based on the performance of the Slim Gems. The Hot Shot electric matches work very well kicking off black powder motors, but it will have to fall to someone with an altimeter system to test them as they are intended to be used. Best of all, you get a dozen (of any of these ignitors) for TWELVE BUCKS!"
I will be testing some of these soon myself.
Thanks,
Nick