I still don't know about synthetic winch ropes. They certainly are safer than wire rope if it breaks, but can be a PITA to use. I hate those hard to work hooks that come with production winch ropes, but some who are making their own ropes use a regular hook. I've also had bad experineces with the rope getting stuck on the drum between other wraps, so we had to hook a rig up to pull the winch line out before the guy who was stuck could winch himself out. We wheel in the rocks most of the time, and it's a pain to always have someone watch the abrasion guard so the rope doesn't get fubar'd. I saw one break on our last trip, and while it just dropped harmlessly to the ground, I was very surprised to see it break so easily. It probably had been frayed slightly in that spot, but that type of damage seems to be hard to avoid. I'd hate to have one of those lines break like that while I'm hanging on it up some steep waterfall or huge ledge.
Wire ropes can be extremely dangerous if they break, but good winching technique and common sense should keep that from happening. The thing that causes damage to a wire rope is the same thing that can wedge a synthetic line between the wraps, and that is driving ahead of the winch. Most people, who don't know better, tend to drive ahead of the winch when winching, causing slack in the line. Then, when they slip again and the winch gets tight, there are loose wraps on the drum that get overwrapped by tight wraps causing kinks in the wire rope (or wraps stuck with synthetic line). These kinks are what damages the rope and where it can break in the future. Proper winching technique is to always keep the line tight when winching so the wraps on the drum are tight. I know people tend to want to (show that they can) drive, but once you have to use the winch stay on the winch and don't let slack get in the line. This is also true anytime that line is taken up on the winch, always be sure someone is holding the line to keep tension on it so no loose wraps get on the drum. Never reel in line with no tension on it, or a kink will be caused when the line is pulled tight over loose wraps. If you're on the trail and someone about to winch has loose wraps on the drum, make them stop and rewind the rope before using it. Also, if a wire rope has kinks in it, replace it.
I'm about to replace my winch line, and I like the idea of the safety and light weight of the synthetic rope, but I'm not sure I'm willing to live with the downsides. I certainly don't want to have to take it off regularly to clean it. I'll probably replace mine with another wire rope, and continue to use it carefully.
BTW, I thought a few words on proper winch technique wouldn't hurt, either.
