I have both. I use the K3iii a lot for birding with the DFA150-450 as well as some general short hikes with a selection of DA lenses. The K1 gets more use for street and architectural photography. I don't get much opportunity for portraiture.
I never carry both.
The major decision to come is which to take on my next overseas trip. I never take the 150-450 with me for those, so that's not an issue. The choice is out of:
- K1 + DFA28-105 + DFA* 50 + DFA* 70-200 + (DFA15-30 or DFA 21 Limited);
- K3iii + DA40 Limited + DA 15 Limited +DA 70 Limited + (DA 16-85 or DA 18-135) + (DA 55-300 or DFA* 70-200).
The final decision will depend on the type of scenery I anticipate, and the weight I'm willing to carry. It will be tough.
No regrets. I wouldn't divest of either.