I have been playing Spiro Weichs for at least five years (former d'addario user). I'm on my second set now, and like them for their sound pizz and bowed and for their tuning stability. The open g string pizzed sounds a little twangy at times, I think maybe I shouldn't dig too hard on the open G. Also, Mittels are to much tension for my bass even at low action, the weichs at a medium height are just perfect. Someday I'll have a second bass with guts for a different flavor, but for now Spiro Weichs are working great.
