@Cyberus
That's not always true. The Motorola qualification levels are as follows:
PC - engineering sample
XC - production qualified
MC - final qualification
Most of the production you'll see is in the XC range. These chips are functionally fine, but are not the final versions and may contain errors (see erata files on Motorola's website for details with workarounds). Once Motorola is sure they've squashed all the bugs they'll move the chip to MC status. For instance, on the 040 and 060 this took 5-6 years.
