I had the good fortune to snap off my whole leader without any replacement. Driving back to the house would have eaten all my time but the only place nearby was a fly shop.  I worked up the courage and walked in the door.  I found a spool of florocarbon tippet, paid and headed back to the river.  

 

Cortland Top Secret fly tippet has turned out to be my favorite leader material by far.  The only high end leader I've used much is gold label and I like Cortland more than that.  

This was on 5X FrogHair, and a size 22 thread midge.  

(and 1918 cane)

 

The YGK leader I buy in Japan is as good as any fly tippet I've ever used.  

 

The threadline tradition revived by the late Dave Witlock and Joe Robinson use small-frame Daiwa 700C modified with finger-bail, load their spools with tippet, and make their rods from fly rod blanks.  

Notice, my buddy Alex didn't butcher his bail.  

I have used it, really no difference that I saw.

The difference between leader and tippet is the whole Hard leader v. Soft Leader comparison.  

If you compare Seaguar Gold and Seaguar Blue to tippet, the Gold is very different, and the Blue is almost identical to tippet.  

You expect tippet  to be limp, doesn't need abrasion resistance, does need maximum toughness and knot strength.  

 

When fluoro was new, Rio High Strength tippet cost me 30+" Alaska rainbow at knot break (standard Surgeon's knot tippet joint).  What good is high strength if your knot breaks with a head shake.  Yes, they backed off on high-strength for toughness and knot strength.