I have played with two different Meucci's and plan on buying another one soon.
My M-4 was made around the early 90's and of course the shaft plays much better than the red or black dot shafts. My brother has a HP-1 with a red dot shaft and it shoots real well. I'm going to buy a HP-3 with a red dot as they feel better to me than the black dots do. The black dots are real 'whippy' to me.
My M-4 also still rolls straight and has never warped, and is atleast 12 years old or more.