Correct bud, no leader. You'd probs get away with the 15 lb with no leader. I know you can really cast so I bet you'd go miles with it.
It's great stuff, hard as nails. I got snagged up last year on some kind of root right in the margins, I had to pull for a break and basically couldn't break it (the line stretched a little before pulling this root right out of the lake bed). Yet it casts (!?!).
I'm going to France in a few months to a water that's all 100 yards + fishing, last year I put a casting line on for this trip but this time I'm just leaving the SLS on, it's absolutely fine.