Some people say they are not that good, but dang Red Nukas are awesome if you are melee. Just have to act fast, get a couple of kills, and go bandage up, it's like a berzerker mode.
Oh, and make sure you are wearing armor that is not important to you, john failed to mention that part.
But other than that it is amazing.
Red Nukas seem long enough to sprint out, and kill a few people, Yellow nuka is over soooo quick, just take it right before you go around the corner and start bursting enemy, and you will have that extra hp for a few seconds.