I use 50/50 strings for days to weeks depending on how much I’m throwing. I change strings mainly because of the string eventually getting grungy, never had a break. I like 50/50 because it stays consistent over hours of play. I’ve never had a poly string break on me, but I find they get ‘fuzzy’ after a hour or so and that affects my play and makes them feel ‘worn’ to me.
To each his own though. Different people are going to look for different qualities in their string. Best to sample different types and find what works best for you individually.