i'll fiddle a bit around with GLSL to see what it is worth speed-wise especially but will not change my render code away from ASM. for something i've got Module System, thus i can add GLSL later on if it proofs good and i have some knowledge about it.

concerning the tangent space i still have no clue why the TBN does 'stretch' my normals instead of leaving the size equal. maybe the XPD function call is defect?