After lots of chopping, changing and experimenting with various leader materials, I'm back with Maxima ultragreen for most things and Stroft GTM for fine work. The Ultragreen seems to suit the way I fish, mighty knot strength, stiff enough to turn over and nice elasticity. The Stroft is softer and better for fine presentation, but is a bit slippery - be careful with knots! When knotting a tippet of GTM to Ultragreen I use a four turn water knot to get best strength. Three turns gives weak knot for some reason, possibly my tying!
BTW, the Stroft GTM is by far the best mono for spinning I have used, really well behaved on the reel.
I think regardless of which leader material you choose, having confidence in it is the most important factor. I have never noticed a difference in takes between flouro and nylon, so I fish with nylon. In my experience, trout are not as "line shy" as many think.
Richard