I own a K-3, and I would not consider it to be a good choice for a travel camera you want to carry with you every day, all the time. Too big, too heavy and too conspicuous. I have not handled a KP, but based on it's weight and size specifications, the minor improvements over the K-3 would probably not justify the expense for me.
Sad fact of the matter is, there is no APS-C camera in the current Pentax line which is acceptably small and light enough for me to carry every day, all the time.
But there is a lot of territory between a K-3/K-P and 'a small fixed lens point and click' - most micro 4/3 and many mirrorless APS-C cameras, with the right lens, can deliver very good image quality without the weight and bulk of a Pentax dSLR.
When I was trying to find a travel camera, my approach was to define my lens requirements first. From long-time experience, I knew I would not be happy with a single focal length, nor I did not want to lug around a bag full of primes and spend my travel time swapping out lenses. So I wanted a zoom, but I wanted better quality than most "kit" zooms. But I wanted to avoid the enormous size and weight of most top-shelf zooms.
My search lead me to Fuji because their XF 18-55mm F2.8-4 zoom is a significant step up from most kit zooms, yet is affordable (expecially if bundled with a new Fuji body) and not too big and heavy. For a month long walking tour of France, I carried Fuji's XC 16-50mm f/3.5-5.6, which is even lighter than the XF 18-55 (and cheaper), but has the same image quality.
A comparison of the K-3 with the basic 18-55mm kit zoom and a Fuji with the XF 18-55mm F2.8-4 <
here>
The Fuji combo, camera and lens, weighs less than the K-3 body alone.