This nylon tailgut is quite a bit more flexible than a steel cable, and it takes a while before it stops stretching. In practice that means that after tuning-up, you'll keep tuning for maybe up to a week, but after that it stops stretching & the bass stays in tune. 
 
Negatives: 
- Continues stretching for maybe a week 
 
Positives: 
+ stretching stops 
+ impervious to humidity changes (like steel cable, unlike real gut) 
+ the larger diameter prevents damage to a soft end-nut 
+ Probably stronger than real gut. I don't know the maximum pull, but with extra nuts it handles 110kg total pull well.