First, either combo will be very good and probably give you very similar IQ.
Now, the differentiators are the following.
Nikon:
Nikon has more accessories and a larger global lens line-up (not APS-C though).
The D7000 AF would probably be slightly better than the K5 in dark light.
If you plan on using long lenses, Nikon will be a better choice as Pentax doesn't have anything longer than 300mm.
The 16-85 will give you a longer and wider range at the expense of speed and DOF. Arguably, the Pentax 17-70 has better bokeh though.
Pentax:
Generally, Pentax has an advantage in terms of size and weight. In the case of your lens selection, not that much though - they weigh about the same overall. However, for hiking having a weather-sealed body is clearly an advantage even if you don't use any WR lenses. You also have the option of cheap as well as pro WR lenses to go with it (18-55, 55-200, 18-135, 16-50 f/2.8, 50-135 f/2.8, 60-250 f/4, 100 f/2.8 macro, 200 f/2.8, 300 f/4).
Ergonomics, features and customizations are arguably better with the K5.
If you go into primes, Pentax has some extremely small and light lenses with great IQ and build quality not found elsewhere: 15 f/4, 21 f/3.2, 35 f/2.8 macro, 40 f/2.8, and 70 f/2.4.
The shutter blur issue was sometimes present on the K-x and K-7. However, it's not measurably the case with the K-5 anymore (according to Falcon Eye's paper).
Regarding the high AA filter. It's a matter of preference and I don't think it's that strong. Images sharpen very nicely.
I personally chose Pentax for the above-mentioned reasons and I can say if I had to do it all over again, I'd still chose Pentax.
I hope it helps.
Now, the differentiators are the following.
Nikon:
Nikon has more accessories and a larger global lens line-up (not APS-C though).
The D7000 AF would probably be slightly better than the K5 in dark light.
If you plan on using long lenses, Nikon will be a better choice as Pentax doesn't have anything longer than 300mm.
The 16-85 will give you a longer and wider range at the expense of speed and DOF. Arguably, the Pentax 17-70 has better bokeh though.
Pentax:
Generally, Pentax has an advantage in terms of size and weight. In the case of your lens selection, not that much though - they weigh about the same overall. However, for hiking having a weather-sealed body is clearly an advantage even if you don't use any WR lenses. You also have the option of cheap as well as pro WR lenses to go with it (18-55, 55-200, 18-135, 16-50 f/2.8, 50-135 f/2.8, 60-250 f/4, 100 f/2.8 macro, 200 f/2.8, 300 f/4).
Ergonomics, features and customizations are arguably better with the K5.
If you go into primes, Pentax has some extremely small and light lenses with great IQ and build quality not found elsewhere: 15 f/4, 21 f/3.2, 35 f/2.8 macro, 40 f/2.8, and 70 f/2.4.
The shutter blur issue was sometimes present on the K-x and K-7. However, it's not measurably the case with the K-5 anymore (according to Falcon Eye's paper).
Regarding the high AA filter. It's a matter of preference and I don't think it's that strong. Images sharpen very nicely.
I personally chose Pentax for the above-mentioned reasons and I can say if I had to do it all over again, I'd still chose Pentax.
I hope it helps.