It gives 8 points extra. I asked the same question couple of months ago.. And the 8 points is actually pretty much, and players can no longer take you out with a single headshot if you have full armor and upgrade cape.. I have all capes but I only use berserker and demolition cape.. The hitman cape gives you a "heart" every 12th second, but since a match mostly takes about 3 minutes, and you probably die during that time, the berserker cape is a better choice in my opinion... The demolition cape can also spare you a lot of health. According to my calculations (which you should definitely not count on), it takes 50% of the damage from self explosion and increased the radius from grenades with 10%, so if you rocket jump a lot, it is definitely a good choice..