On my DGT, I can usually go for at least 30 hours of play time before I break a string, and often change earlier because of the strings getting dirty. I don't think I've ever broken a string on my CU24.
But on my Siggy (Stoptail), I'm breaking strings after less than 5 hours play time consistently. This seems a bit abnormal to me. Does it have something to do with it being a stoptail while the others have trems? Is it an issue with the nut? Some other issue?