I used to use Thomastik Belcanto for academic orchestra and solo playing, then I tried Pirastro Passione and they changed everything. Amazing great delicate sound, you can make a lot more colorful nuances. Not only they sound great, you can play a lot easier, especially harder technical pieces, small notes in passages are clearly audible, not mushy at all. You can also play a lot faster than before. Also my bass wolf is almost gone. Then I tried again Belcanto's as they are cheaper and realized what a mistake it was. My year old Passione's performs a lot better than brand new Belcanto's.
I highly recommend these strings for academical orchestra and solo bass playing. These strings are one of the best double bass strings out there.