KMS Graff Spee is a very good ship when played right. I like to use it in support of a BB and to kill cruisers. The torpedoes are really good against battleships. One thing I do is to not lead the charge in the beginning as too often it has bad results. But paired up with a BB, it provides excellent support. When supporting a friendly BB against an enemy BB, I prefer to shoot HE and set the enemy BB on fire and then switch to AP. Most of the time the enemy BB is firing at the friendly BB giving you a free shot at them. It also makes it easier for the friendly BB to take out the enemy BB. If the enemy BB gets too close, you can give the enemy BB a torpedo sandwich for lunch!