head gasket failures on benz engines typically manifest as external oil leaks. by the time it reaches a point where there is loss of compression through there i would venture to say that the head is already warped from overheating. i had the well known head gasket failure on the m104 and i had neither power loss from compression, nor overheating - just a really annoying oil leak...
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"