Originally Posted by ricardobeat 
The 4/3s system was designed to eliminate CA and other digital aberrations
The 4:3 system? What does that mean? Just because of the sensor size it doesn't get CA? Do you mean that if you stick Oly's 70-300mm lens on a Pentax body, it will have PF & CA all over the place?
That Oly lens has 3 full ED elements in it for $349. Does the Pentax 55-300? I mean Hoya owns them! It should have 4 ED elements!
If the 4:3 system has been designed to eliminate bad lens IQ, then Pentax should figure out a way to design APS-C system to do that.
I mean you tossed away a Tamron 70-300mm like it was a piece of disgusting junk because you got a bad sample with excess PF, and I love mine. The bit of PF I get can be processed out like you say, but for the $200 extra price of a camera brand lens, Pentax should design lenses that work with APS-C eliminating CA & PF.