I have been settling into a routine for my photography and using the Pentax K-1 II camera with the 28-105mm lens for my personal photography and the Nikon Z5 with the 24-200mm lens primarily for Homewood photography.  They are both full frame cameras and I can use either one to back the other up.  I prefer the Pentax for walking about when I occasionally see wildlife or need the better LCD for down low detail photography even though it weighs 6.5 ounces more.  I also prefer the Pentax for cropping and processing images.  For Homewood photography I generally use jpegs with minor processing.

The primary usability differences other than size and weight are:

The Nikon is silent.  The Pentax isn’t.

The Pentax is more rugged and weather resistant.

The Pentax has a 36MP sensor, the Nikon has a 24mm sensor.

The Pentax has a rugged multi-tilt LCD, the Nikon’s is more limited in flexibility.

I prefer the hand grip, controls, and ergonomics of the Pentax.