Well the 412 "classic" has a smaller fuel system than the SP (5 cells versus 8) so I suppose it might be a bit lighter but I really can't imagine how it would outperform the newer bird with strakes (but no fast fin?)
Does the straight 412 read mast torque or is it the same as a 212 where it takes the total of the two single engine torques read at the c/box?
I don't know how it is on 412's but on 212's the difference between a good set of M/R blades and a bad set can be quite noticeable.
What are the empty weights of these machines?