I don't have this particular item, but I did buy a similar product, one of the first, a LaserBlaster, several years ago for much bigger money and was caliber specific. Not sure if they're made anymore, but overall, I've been happy with it.
Positive results? Your point shooting skills will improve dramatically. And batteries are much cheaper than live ammo.
The only bad thing about mine is that it doesn't fit completely within the barrel but sticks out about 1/4" so that presentation practice from a tight fitting holster isn't possible. But iI use it more as a propiosceptive training aid at 10 yards to better "know" where the muzzle is pointing so thats not really a big issue (for me).
YMMV