I'm of the opposite opinion of the two posts above. I tried them, and prefer tapered mono leaders with the addition of a tippet ring. They do turn over a fly more reliably than a mono leader, but they also don't tend to sink when you want them to (streamer fishing), and are more expensive than mono leaders. With a tippet ring added to the end of a 2x or 3x tapered leader I can pretty much fish the same leader for a whole year, and I can keep a leader on each reel I have, so the mono leaders just seem more versatile to me.