I haven't used any gut strings for decades, but after hearing praise for the sound of these strings, I decided to try them. I was not happy with the way the Evah Pirazzi Gold G responded on my instrument...it is finicky and too often "cracks" in higher positions, and was a little harsh. I replaced it with an Obligato, which was more solid and warm, but sounded a bit dull.
The Passione G is, on my instrument, the best in terms of sound and response. It is not only warm, but seems to add a quality of depth (hard to find the words) and ringing quality that the others lack. It has plenty of volume. Now that it has been on my instrument for a week it really smoothed out and sounds lovely.
The only down side is that it did take about a week to settle in, It still seems to need tuning more often, (as does the D which I also replaced, and has the same ringing depth added to the sound). It will be interesting to see how it evolves.