i think glTranslate alone is faster than making translation matrix and multiplying *only* because glTranslate doesn't have to multiply 4x4 matrices together. But of course for complete transforms(rotation&translation) it's faster to compute matrix yourself and then glMultMatrix.
It's just matter of math optimizations for incomplete transforms. If optimizations in glTranslate and glRotate give no benefit (you gonna to do complete transform) , it will be faster if you'll make your own matrix, but only if you do it in not too stupid way.(if you'll make translation and rotation matrices, then ordinarly multiply 'em together, then glMultMatrix , it will be slower, if you'll make rotation&translation matrix in one step and without doing unnecessary math operations, it might be faster)
