Is the double knee worth it over the standard Dickies work pant?

If you kneel or crawl regularly, yes. The second layer at the knee is the first place a canvas pant fails, and it noticeably extends life there. For standing-only work the standard pant is lighter and cheaper.

How does it compare with Carhartt double-front duck pants?

The Dickies is lighter and breaks in faster, and the cut is roomier. Carhartt duck is heavier and has more tool pockets and a gusseted crotch, so it suits buyers who want maximum toughness over comfort.

Does it fit over work boots?

Yes. The straight leg is cut wide enough to sit over most work boots without bunching. The waist runs roomy, so check your measurement before ordering.

Will it shrink after washing?

Cotton canvas can shrink slightly, mostly in length. Wash cold and line dry to limit it, and expect the fabric to soften at the same time.

Does it have knee pad pockets?

No. The double knee is a reinforced fabric panel, not a pad insert sleeve. If you need internal knee pads, look for a pant with dedicated pad pockets.