I am about the biggest Nanofil pimp on the planet. I freaking love it and while I will admit it has some downsides overall I think it is the best thing I have ever tried on spinning and remains one of the very best things I've ever done to improve my fishing success. I fully reccomend it. I do not tie directly to my leader, but instead join a supple mono or copoly with an alberto knot.
Many though are equally happy using any one of a number of braided lines. I wish them continued success and I will continue to listen to trusted opinions about new braided lines on the market and *gasp* even straight fluro on spinning. The pro ranks have almost universally gone to braid with fluro leader material, but I never see the reasons for why they use fluro as their leader.
What I continue to long to have explained to me is the almost universal use of fluro as the leader for those that fish with braided line and leader on their spinning gear. To me, the downsides of fluro as a leader in this situation outweigh whatever advantage it might have. I am more than willing to give it another chance IF someone can make a compelling arguement.
The disadvantages to me are that 1) fluro is picky about knots. If it gets hot during the knot tying process, it is significantly weakened 2) it is a thicker line than many other choices for leader and usually stiffer as well. It may be less visible, but the subtle effects on the bait may be more noticible. 3) the combination of no stretch mainline and no stretch on leader doesn't offer any advantages and may lead to more breakoffs. I don't think the stretch in 6 foot of mono is going to affect sensitivity negatively and may offer a tiny cushion on the hookset. The rod should give some and you don't have to gorilla the hookset, but still 4) the initial expense of the fluro leader is higher and 5) i'm not convinced that most fluro lines really offer a whole lot of extra abrashion resistence.
Please enlighten me.