I tried these on my rather resonant, "Italian sounding" violin, and I'm really liking the powerful, rich tone, and quick response, and the instrument Just Works(TM) with these strings. I'm going for another set!
And yes, I'm using the full set. This violin has had some wolf-like tendencies on the lowest notes on the E string, so I've used various whistle-free special strings (though I never had a whistle problem with this violin), as they somehow eliminate the wolfiness as a side effect - but with the PIs, that problem is gone.
Prior favorites are Evah Pirazzi Gold (responsive, big sound, can be played aggressively without choking), and Warchal Timbre ("brittle," sophisticated tone, instant response), which both sound great, although quite different. I'd say the PI is somewhere in between, possibly even combining the best aspects of both.
As for durability, I've used my first set for about four months, and while I'm starting to notice minor tuning and response issues, they're still perfectly playble! An Evah set tends to be dead after about two months in my experience, whereas a Timbre set can last for up to half a year (!), so I think the PIs are doing alright in this regard.