Firehouse flex is questionable. I have 3 pair and they are probably the most comfortable pair of pants I’ve had. However, I use a pocket knife and small flashlight clipped into my front right pocket frequently, and within a year the pocket seam is torn to shreds. I have three pairs and wouldn’t dissuade you from them, but depends what you do. I also have 2 pair of under armor enduro pants. These have surprisingly held up much better than the Duluth. The Duluth shrunk up an inch or two in length as well after a few months of use. I work as a shop floor engineer for heavy equipment and frequently do mechanic-esque work FWIW.