I have worn them in small gravel and dirt trails. Manual labor with often 15k+ steps a day on carpet, concrete, and pavement. Heavy lifting and crouched/on my knees. Urban travel in rain and snow. Extreme cold with thick socks, and warm outdoor work with lots of sweat.
It ages very slowly and gracefully. Started to develop a few rolls pretty quickly along the ankles and toes. The break in was pretty smooth, as these are fully kip leather lined. The tongue wasn't super comfy, as it was thick shell with no backing, and the left tongue never stayed centered. Took on occasional water spots, but those evened out quickly. Sweat/salt stains showed through at a few points, but mostly brushed out after a little wiping with a damp cloth and horsehair brush. I wiped them down if they accumulated mud, etc. I had to pick small gravel and pebbles from the tread occasionally. I only brushed once a few months in, and once at the end of the six months for the final submission. I wore them hard and didn't baby them. Very little maintenence.
It's a comfortable and solid combination last. The heel is snug, but the forefoot with high side walls is very forgiving. I wear them mostly with wool work or padded sport socks. No pinky toe crunch which I often experience with prolonged wear on even well-fitted shoes on most lasts. Still manages to feel supportive and not fatigueing after being on my feet for 12+ hours a day. And this pattern looks classy and professional, but great with more rugged and casual fits.
Grant stone finishing is best in class by a mile. Have to spend twice as much to get comparable QC and sleekness. Their materials and construction are well documented: leather, cork, steel shank, and not much else. Outsole stitched through. The clicking is always solid. The Brass Boot pattern just works. Perfect balance of rugged, casual, and smooth. Halfway between an Indy boot and a Redwing moc.
Very versatile. Takes on some pebbles and the like in the studs that has to be picked out. Solid traction in water and snow, but not too grippy to make you stumble on carpet or hard indoor floors. A little chip came out of the toe on one boot, but it hasn't compromised the lugs and it's still stitched on. It's not as forgiving as a wedge, but it has enough bounce for general use and long days.
The tongue might benefit from being either a thinner shell or a different leather article. Also tends to slide to the side. Couldn't train it to stay center on one boot no matter what I tried, even with the partial gusset. Would have loved a half lining. Maybe an unlined shaft. These can get sweaty. Hard to beat the price and value proposition with GS shell boots. Even with the recent price increases.