Interesting question and a tough call that one Mr B
I am very fond of the upper river (oddly enough
) as it was my introduction to the river.
But I like it all, I just don't have enough time to fish it all
If I had to say why I really like fishing the upper river (say Alford up) then it would be because it's a very 'highland' stream with plenty of challenges for the angler - and it's remote, a great place to get away from it all for the day.
Hamish