Laser Cartridge Training

There are several laser training cartridges on the market now for slow fire training. They use a laser activated by the firing pin that projects on a target. The hits are recorded by cell phone or tablet. Much of the software is free. Laser cartridges are $25 to $90 .
 So who has tried these and are they of any benefit? What brand is best for Bullseye slow fire? Durability?
Many have bells and whistles for the run and gun that I am not interested in.
Any comments appreciated.

My experience was they are not accurate or consistent enough for BE training. IMHO would do more harm than good to a new shooter trying to learn the fundamentals and learning to call their shots.

Hi, I use a LaserLyte with a piece of 2-way tape on my Pardini HP with the CF 32S&W barrel. The LaserLyte uses an accelerometer to activate the laser. When the hammer falls the vibration from the hammer strike activates the laser. I use it at 10M as I have a 10M shooting lane for air pistol. Seems to work good. It does give really good follow through training. If I am not perfectly smooth with follow through it will not mark a 10 but the lowest place/score as the laser stops on the target.  Of course YMMV…