I have been flying the Typhoon for quite some time. Here is my experience:

The Typhoon servos are not as good as their recommended replacement (HS-81 servos).

Adding to the problem of weak servos on the stock Typhoon is the fact that the rudder and elevator are very stiff requiring very strong servos (unlike the ones supplied with the stock plane).

The first thing to be done is to loosen up the elevator and rudder so it takes very little effort for the servos to activate them. I did this by actually cutting the plastic connecting the elevator and replacing it with regular hinge tape (others have cut only sections of it). If I don't have the pushrod connected to the elevator, the elevator will fall just due to gravity. Check it out to make sure that happens. I was able to loosen up the rudder by flexing it lots of time so I did not need to use regular hinge tape with the rudder.

If you keep the elevator and rudder that loose, the stock servos will last you quite a while if you don't have any crashes. If you do crash, then those weak servos will not last very long. I had a couple of bad crashes with my Typhoon plus a "cartwheel" during a landing and the stock servos were stripped. I replaced them with HS-81's and had no problems.... but also, I don't crash it anymore!