Interesting you should say that Giogio. I have the modern day Fenwick FG765-3 I bought from Dette Flies In NY on close-out awhile back, so I do have a 7'6" 5 wt. In fact, I'm pretty sure I read about it's availability on this site. At the time, I thought I should have a 5 wt. rod, and the vintage 5 wts. were hard to come by or were nearly as expensive as a new one on the auction site. Turns out, I like the vintage 6 wts. better.
I have noticed that the FF86-5 is softer than the FF865, which was a surprise. I figured that with the 3 additional ferrules it would be more stiff, but it's not. I also have both 2 pc and 5 piece Fenwick 8 wt. rods, the FF85 and FF85-5, that I like very well too.
I guess the thing I like best about these rods is that I can easily feel them load, and it has helped my timing significantly. And that has helped me a lot with casting any fly rod!