samsung has an inherent optical drive mechanism problem..
and secondly all samsung writers use
variable velocity method on thier drives,
but in asus and sony writers(which i currently have)
they use constant angular velocity system,this means the read and write speed will not differ when the laser goes from the middle of the disk to the end of the disk..
i m not sure whether samsung is a good bet,cant say the same for thier DVD drives also..