Sign me up with the floro crowd. I find I seldom need to go as small as 5x with it, except to get it through small eyes on small flies. As a rule of thumb I can use one size heavier leader than mono without spooking fish while cutting down on the break-offs.
I depart from everyone here though, in the butts. I use heavier than 0x in my butts, but
PLine Floroclear Copolymer for its stiffness. Their Shinsei (same link) should be just as good, and perhaps easier to find far from Alaska salmon waters. You just won't believe the improvement a stiff leader butt will make in turning over leaders, whether with heavy flies or long leaders with dries.
One key I've found if you're switching between mono and floro in a leader. Match the
diameters of the two types when you make the transition rather than stepping down one size, then continue with the step downs at the next joint. By that I mean you might go 0x,1x,2x with mono, then mate 2x floro to the 2x mono, followed by the usual 3x,4x,5x with the floro. If you go directly from 2x mono to 3x floro, it dramatically cuts down the strength of the 3x.