I had purchased this as the rebranded version through LL Bean.
The only difference is the branding (Katadhin Iron Works Engineer), the lifetime satisfaction guarantee, and the LL Bean version also has a toe cap.
Unless you are sold on the toe cap (as I was) it is a better price here on Amazon.

The leather is top notch.
A thicker cut is used unlike many boots on the market, with double and triple stitching on most seams.
With the oiled leather it is not neccesary to use any additional protectors, but most people will tell you it is a good idea.
I had applied a layer of Mink Oil first, allowed this to dry and applied Obenauf's HD Leather Protector.
SnoSeal will do nearly as well as the Obenaufs at a cheaper price.
All of this darkens the leather, but my preference is a deep brown anyway.

By doing so not only did it soften the leather to make the break in easier, but the water just rolls off, and any dirt is easily wiped away.

I mentioned the break in period, as it can be rough going.
The type of leather used, while wonderfully solid and durable, is tougher to break in.
Most people recommend a 2 week minimum if worn most of the time, and up to 2 months if worn intermittently.
So long as you size it right, this will mold beautifully to your foot like a glove.
The top collar rubbed my right ankle quite a lot at first, but after nearly 2 weeks I only feel the slightest pressure on that side still, and expect this to go away after a short time.

I typically wear size 11s, and picked out the 10.5 as they are known to run large.
FYI I wear size 10 Doc Martens, and size out to a 10.5 in the Red Wing Iron Rangers as well.
Keep in mind it is a bit more narrow than most boots, so order the EE sizes if you have wide feet.
I am on the borderline with width, but after the break in, the leather will stretch and mold to a better fit on the normal D  width.

There are many online reviews of people using these boots for 10 or 20 years.
Treat them right, and you can expect the same, as I do.