I have been using these strings for a at least a year on a 1940's Italian violin. They seems to last at least 6 months without losing any tone or projection. I was using PI strings before and finally just lost interest in how unpredictable they were and even the sound they made. The Perpetual (regular, not the cadenzas) strings seems to have everything that I have been looking for for some time- tone, projection,dynamics and consistency.
Note: I use the G, D, A, for the E, I use a Heavy gauge Gold Lable.
I highly recommend these strings!!!!