Racing sailboats, I use miles of Amsteel, and other (better) lines. Amsteel is cool stuff, in that it has a phenomenal strength to weight ratio, but has several disadvantages. First, it's not UV stable, meaning it will fairly quickly deteriorate in the sun. Second, it's a single braid, which runs nice and fast thru blocks, but is almost impossible to hang onto (maybe not a huge issue for winches). It does not hold knots well, and is fragile with respect to abrasion.
I have Amsteel on my boat, in a few control systems (twings, topping lift, etc.) where minimal weight is key, but I would not want it on a winch in the woods!