I own a couple.
They work great for shooting field rats off the tractor!
They will not pattern like a regular .410 shotgun because they have to be rifled...which spreads the pattern faster than usual- great at close range, which they are designed for.
A bit ammunition sensitive- but all .45 Colt handguns that "happen" to take a .410 hull can be. Stick with Winchester, Remington or Federal and you have no problems.
The advantage about getting a 3" version is if you already have something that takes 3" shells only. The disadvantage is you can't get a lightweight with a 3" chamber.