Just a better intonation and ultra low tension due to the construction.
Almost all my basses are now equipped with these Hellborg strings and some fretlesses have received the flatwounds that are even way more expensive.
Beware that the B string construction on both ends is really massive so won't accommodate all basses.
And never cut them before fitting whatever bullshít Jonas Hellborg himself may have said and he's a master at it as, even if I'm a huge fan of his music, this guy could put his name on manure.