I don't really know which things people mean when they say "refined." I think some mean "the controls fall easily to hand and the displays are easy to read," and some mean "turning the controls feels like butter."
Some of the obvious issues (refinements) in the F-F2-F3 series are the improvements in back hinge, metering/display, and the move to AI indexing. But if you aren't going to use the meter then the latter two don't matter.
Without metering, I think the difference between them is pretty minor, compared to the difference of F/F2 versus later, smaller SLRs (like an Olympus, Nikon FE, etc). Apart from the meter, the F and F2 are both overbuilt machines that feel like winding a very solid industrial item with no looseness. If you get one in good condition it could likely last a lifetime.
Just to throw a wildcard in, if you are comfortable with the around-the-lens shutter ring of the Olympus, you could also consider a Nikkormat. They're about the same size as an (unmetered) F/F2 and also very robust, not the top of the line, but there are a zillion working ones out there.
The operational feel of the camera will also depend on the lens. Older Nikon manual focus lenses have a nice solid feel to the focusing and aperture, assuming they haven't been beat up. Some of them have been used very heavily and no longer feel as nice, so bear that in mind.
Some of the obvious issues (refinements) in the F-F2-F3 series are the improvements in back hinge, metering/display, and the move to AI indexing. But if you aren't going to use the meter then the latter two don't matter.
Without metering, I think the difference between them is pretty minor, compared to the difference of F/F2 versus later, smaller SLRs (like an Olympus, Nikon FE, etc). Apart from the meter, the F and F2 are both overbuilt machines that feel like winding a very solid industrial item with no looseness. If you get one in good condition it could likely last a lifetime.
Just to throw a wildcard in, if you are comfortable with the around-the-lens shutter ring of the Olympus, you could also consider a Nikkormat. They're about the same size as an (unmetered) F/F2 and also very robust, not the top of the line, but there are a zillion working ones out there.
The operational feel of the camera will also depend on the lens. Older Nikon manual focus lenses have a nice solid feel to the focusing and aperture, assuming they haven't been beat up. Some of them have been used very heavily and no longer feel as nice, so bear that in mind.