I've had the pleasure of using Obligato string sets on my cello for a couple of times now. They live up to the reputation: they're powerful, incredibly warm, quick to respond, and fast to break in. Despite the power, the Obligato strings have beautiful nuance and overtones. They deliver a range of sounds, dependent on the song's needs. I haven't had much experience playing with other musicians, but when I have (I've played duets with piano and with a second cello), my cello was able to stand on its own without overriding my musical partner. The A string is much too bright on my cello, which I've heard can be an issue. It seems like Pirastro wanted to make sure projection is maintained on the A string, but on my instrument, it's just a bit too strong. Pirastro recommended replacing the A string with their Passione A string, and it fixed everything right up. My current set is now Obligato C and G with Passione D and A strings, and I couldn't be happier. The two Passione strings mellowed out my boisterous cello without taking away resonance. There is a slight shift in tone from the Obligato strings to the Passione strings when playing pizzicato, but when bowing, they blend perfectly from string to string. I won't be changing away from this line-up any time soon. These strings are everything they claim to be.