I have two pair and I wear them all the time. My first pair, bought in 1998 and on it's second sole, is almost polish free except for an annual wipe down with some mink oil. Nice lightening of the dark leather along the joint with the sole and at the toe. Nice.
The newer pair, maybe 5 years old and the pair I wear with socks on Fridays or anytime I wear khakis and such, has darkened from the original out-of-the-box reddish tint. I use Obenauf's boot oil mostly but have also used Red Wing boot oil and plain old mink oil. I also take them to my favorite shoe-shine location in Atlanta when I'm up that way and have the gentleman give them a treatment with clear polish. They take on a deep luster. Enjoy yours!