Comparing MIA and MIM P basses

[Batmensch]

Strings are certainly not a factor to compare MIM to MIA.

Otherwise, practically speaking (with my 2011 P Basses - MIM & MIA), the main differences are:
Pickup (MIA = Moderately Hot & Middy, MIM = Very Hot & Trebly)
Truss (MIA = Graphite at neck heel, MIM = Steel at nut)
String thru option (MIA = Body or Bridge, MIM = Bridge only)
Shielding (MIA is better shielded than MIM)
Hardware

Again, the truss rod is NOT graphite, the reinforcement rods are.

 

[cmarko]

Again, the truss rod is NOT graphite, the reinforcement rods are.

Do you think it's possible that the Reinforcement rods affect the tone on the instrument ?

 

[keep it low]

Meheecans destroyed my neck insert, look at all the stray holes I mean cmon! There aren't any termites in there!