What do you want the body armor for? What threats are you preparing against?

For myself and the threats I think I'm likely to face, I've decided against body armor. To be effective, you need to be wearing it or have enough warning to put it on before the threat presents itself.

Also, the added weight and bulk can have a significant impact upon any use of a firearm, especially if you're using cover, moving, or using any shooting positions that aren't on two feet. This means significant additional training time. My training time is constrained as it is.