I have a nice yellow one that's 30 feet long. It's great as long as you are going straight with it. You can't "bend a leg" in it like you can with a steel tape, so I stick with steel ones for routine fishing. The fiberglass one is really nice if you are, say, fishing across a ceiling since it stays flat instead of possibly coiling like steel tapes can do. Remember that fiberglass tapes are a bit stiffer, so working with 1/2 or 3/4" pipe might be tougher since these tapes don't bend into a tight radius. I have had mine for about ten years; no splinters or anything like that. I have lost one of the end eyes, so have to just tape the cable onto it.
I have an Ideal one that I fished out of the dumpster at the supply house. Somebody didn't like it. Had a kink at the end so I just cut a couple of feet off. This is the plastic flexible one and it goes through pipe great. Don't expect to fish walls and ceilings with it though.
For ceilings especially I have the fiberglass rods. They do shed splinters after awhile. I'll have to try the lacquer treatment, else wear gloves.
I have a fiberglass one and it is awesome, it is the only way to go when fishing greenfield, I have gotten the fiber snake through a few underground runs where the 1/8" steel wouldn't go. I have had it for about five years and no splinters as of yet. The only complaint was the price, I think it was around $130
yeah, they're good for a lot of things, fishing unknown, abandon conduit runs is nice, *steel hooks on edge of abandon conduit* "Will, go up in the attic (contaning many rat corpses) and find where it got hooked"
they do have a problem with the leaders coming off, I believe Ideal replaces the leaders free of charge for a year or so?