The plasma grenade requires a lot of pratice to use correctly. Its longer fuse means it can be used for traps. It can stick. It is stronger. Howerver it glows. There are two good ways to practice use with the Plasma grenade:
1. Go into the Arbiter on Heroic and legendary. You can also try the Plasma grenade/ Plasma pistol combo.
2. Start a plasma pistol only game on midship. Use Plasma grenades only.