Neatsfoot oil has the benefits of stay a liquid no matter the temperature, so it never hardens. However, most neatsfoot oils are mixed with rapeseed or mineral oils. Mineral oils will speed the breakdown of the leather and any stitching. Pure or compounded neatsfoot oil can oxidize over time and signifigantly darken the leather. It is an animal fat, similar to lard-- it just melts at a lower point.
Mink oil is more like the human sebum (or hair and skin oil). It can be used on all leathers as both a conditioner and to protect. It also works as a waterproofer and can be used on extremely dry hands or skin in the winter (so long as there aren't any potentially harmful additives).
Saddle soap contains neatsfoot oil and usually lanolin and glycerin.
For your rugged boots I personally would use mink oil unless they are dirty (then saddle soap). Most polished dress boots can be waterproofed with mink oil or you can use a clear polish in liquid or solid form (you may prefer the liquid for darker boots). Sprays work best for boots with a suede or fabric component-- imo.