A Weight bat is a great way to help improve your game. Also, before at bat they want to feel like their swing is great, so use a weighted bat to feel lighter at the plate. Having a bat weight is a common thing among teams, but it does not significantly change the feel of the bat. A better option for this purpose is a weighted bat. These are a better option because the weight distribution of the bat is much better than just throwing a weight on there. This is the simplest way to describe why using a weighted bat is better.
Besides having a bat for the on deck circle, there are bats specifically for training. The purpose of these bats is to swing something that is substantially heavier, so your regular bat feels like a feather. Using this as a batting tool is extremely helpful and will ensure great bat speed. I mean what is the ultimate goal in a swing? For many, it is having great bat speed, in order to turn on balls and hit fast pitchers. Using a bat like so can do no harm, the only thing it will do is speed up your swing. That is if you use the bat right. Some misuse the equipment and disrupt their regular swing, leading to long slumps.
The two options you have when it comes to these training bats is the on deck circle and in cage bat. Each has it uses that help hitters improve their batting averages. The bats that are for the on deck circles are generally a cylinder shape, so weight distribution is even. The training bats for the cages have the shape of a regular bat, but are obviously just heavier. These bats will be able to keep your swing the same, because the weight is distrusted like a regular bat. Training bats for the on deck circle are just to get something heavy in your hand before your at bat. Likely, players only take a few swings with the on deck circle bat, so they do not jeopardize their swing. These are the main points of these training bats.
If you're wondering which is more useful, you have come to the right place. Training bats for soft toss and cages are generally more useful. This is because you are going to be swinging one more often. You will be doing your off season work with the soft toss training bat, so it will get more use. I suggest having both as before at bats it is always great going to the plate knowing you feel like the bat is extremely light. This is the big plus of the on deck circle bat. It provides a drastic immediate change whereas the cage training bat will not effect your swing weight feel on the field.
Both are great training options and should be on every team's arsenal of training equipment. For overall swing performance, the soft toss training bat is the better option. But, if you're looking for a balanced immediate change in the feel of your swing weight go with the on deck circle training bat.