I just put down $40.00 on some Fireline XDS in 50lb test (300yds). It is as advertised as being stronger than regular braid, however, 50lb test XDS is stated as having a 15lb diameter. Looking at this stuff, it looks more like 20lb test to me. Looks kind of stiff too.
Lately I've been using Power Pro 50lb test braid and it sure is a heck of a lot thinner (actual 12lb test diameter).

Maybe I'll try the Fireline on my 11 footer with a 706Z for rough conditions. Im surious as to how far this stuff can cast.