A body wave is to give hair movement and volume. The amount of curls can be reduced in the hair this way also. Your hair should have renewed shine after wave.
I think you should get one if you are prepared to re-perm it every so often. Just like hair color, perming takes maintenance. When it grows out a bit, your hair will be in a body wave and the rest will be your own hair.
A body wave is helpful if your hair is very straight and fine. The body wave will give fullness and a slight wave. It will also help your hair to hold a curl. Be aware that this is a chemical process. Hair should be in good condition for best results.
If your desired look is to have more body in your hair, then that is a good thing to get. You will not need to use curlers as often. It is also still easier to comb your hair than a regular perm would be.
Yes, it is always beneficial to get a good body wave if your hair is perfectly straight and limp looking. It will greatly improve the manageability of your hair.
