[VFB] New fly lines

[Tom Davenport]

I've noticed ads in the fly fishing books for new fly lines.   
Cortland has its new "Precision" line which touts Species Specific  
lines and tapers; Rio claims their new ingredients "Agent X" and SFT  
combined using "Fusion technology" make the best floating line in the  
industry.   And I also remember reading about a new line  
"specifically designed for today's faster rods" being sold by  
someone, but I can't remember who.

Has anybody tried any of these new lines?  Are they real improvements  
or is it just typical marketing hype?

Has anyone found a brand or type that they feel is  significantly  
better that its competitors?

Tom