I just put a set on my bass today, Love'um! I was using Corelli 370tx for the last ten months and was getting a nice arco response and a nice pizz sound, but the E was too weak, and even though I liked the bright tone they had it started to get to me for some reason this month so I though I'd go with darker & smoother sounding strings. And so I order the Jargar fortes. So far in the hour they have been on I'm getting the best arco response I've ever got on this bass. Pizz isn't thumpy or boomy but very old school, slapping sounds nice as well. I can't wait to see how they sound once they settle from where they are now.
Tension vs Corelli 370tx: G&D less, E&A more, but easier to play over all.
In one word: Smoov

.
Edit: After a few hours now, they are really opening up, very round sounding and the volume is closer to Spiro reds then Corellis or superflexibles.