After using Berkley Fire Line for the past 2 years, I'd never go back to monofilament. Strong, small diameter (actually it has kind of a flat cross-section), sensitive, a totally different feel. There's very little current drag/resistance.And few if any loops or birds nests. The down-side is if you usetoo heavy lb test and get snagged, it's almost impossible to break.

And you can cast a mile with this stuff.