Hmm, logical reason for staying with Pentax?
There is none. Or there is zillion reasons.
Let's make a small diagram...
Why did you choose Pentax in the first place?
Do these reasons still hold?
IF No THEN
IF (you have enough money to change systems) THEN (go through all the thrills and chills of selling your equipment and buying another system and be prepared not to be satisfied because the grass is always greener on the other side)
ELSE stay with Pentax
I hope this helped.
Branimir
P.S. You could also outgrow your camera. If that is the case, choose your new camera from wherever you want. But remember - cameras are like a hammer and chisel. One could be diamond coated (Pentax
) the other plain steel, but that would not matter to Michelangelo. You are the one making pictures. You could buy a new camera (FF, medium format, P&S you name it) and make better or worse pictures than you are making now.
I have recently been pleasantly surprised how good some of my pics turned out to be.