Obviously, as has been stated so many times, different designs offer different advantages. So if a certain one fills particularly important needs for the individual, changing to it makes sense. Also, there is nothing wrong with having equipment from more than one manufacturer to meet one's needs.
---------- Post added 09-13-18 at 03:17 PM ----------
Originally posted by GlennG Likely stay with Pentax and restructure the kit. I'd get a Kp, 15, 20-40, and 70 limiteds and stop there. My wants/needs have changed over the recent years is what is driving that change. I'd stay with Pentax for the value, performance, and familiarity. But, other tempts include Fuji and micro 4/3's. I think Pentax still wins out, however.
Indeed. One of my favorite ensembles. I just got the DA 70mm LTD. having talked myself into it on another thread! I also add the FA 77mm and then as an extender, the DA* 50-135mm. All in all, a very compact kit for what it is.
So as to "Why Do I Stay With Pentax"- it begs being answered with another question: "Why wouldn't I stay with Pentax?" What should I do- sell everything and go to CaNikon and pay for WR lenses starting around $1,000 each? If I had an especially important need like a lot of fast sports shooting where my Pentax gear isn't making it, I would consider adding a Nikon D500 and appropriate lens for this purpose. Nikon is also noteworthy for their superior multi-flash setups. (although I have shot some fast-moving sports with my Pentax gear. The Nikon D500 is simply formulated for fast-tracking, high FPS burst shooting)
A few years ago, a retired family friend whose background is in marketing, with shoot setups, etc, went from using Canon DSLR equipment to a smaller Oly outfit for his own use. Lenses are remarkably small, due to the smaller sensor, and he says it yields fine results for his needs. He travels a lot. I handled his camera and some lenses, took a few shots. I was also shooting with my K-5IIs. For me, while the smaller size of the Oly outfit was very impressive, and desirable, I still liked my Pentax K-5IIs better. Better control set, and features like the Pentax Hyper System, etc. Built-in flash. Great build and handling. Those complaining about the smaller grip of the KP would certainly not like the Oly design.
Later, along came the KP. Comparable in size to APS-C compact mirrorless, it was a definite draw for me as a compact higher-quality alternative. Wonderful features, built-in flash. Great control set, nearly as good as my K-5IIs, and fine build quality. Many advanced features. Changeable feel with the different grips, and an available battery grip. Actually, with my DA* 50-135mm, it weighs around 1/4 lb. less than the Oly and its smaller sensor with its 50-140mm. I am very happy with the fine results I get from my K-5IIs, and my very small K-S2, but the KP is delivering results that amaze me! VF, AF, build quality, everything is highly satisfying.
I do know Sony has long been a leader in video cameras. Their continued success in cameras featuring video does not surprise me. Their FF mirrorless has also been in the lead, and continues to be impressive. It does also save weight, but a big FF tele lens is still big, and the EVF and control set is not to everyone's liking. I don't have the FF K-1, but should I get one it would essentially be with shorter lenses in mind. My Pentax APS-C equipment has been delivering great results for me.