Well they actually make overall performance better. You won't get more fps from one, but you will get more consistent fps because of one. After using one, I could never go without one. I love having my computer boot up in about 15 seconds. It is also very convenient when you want to do a fresh install to have a boot drive with only your operating system and the games and programs you use most. You keep your important files backed up on the hard drives. So you just re-image the computer quick and easy.
But the decision is entirely up to you. You can just take it out of the build I made you. What do you think of the build I posted?