My first two years nursing I've done three hospitals. I stuck a year out at a large organization that I hated. It was disorganized, the ratios were awful, management was difficult to work with, turn over was very high. I went to a smaller hospital closer to home and it seemed better for a little while but in many ways it became worse when season hit. Safety just wasn't a priority for that hospital at all and the amount of sentinel events and deaths was a bit terrifying. Since then life has changed. I'm at a large network and I work a pretty high acuity and I'm happy with what I do. A lot of the happy as to do with my co-workers and management. Moral of the story - big and small can all have problems.
In less than three years I hopped through three networks. Is that ideal? Probably not. Still - you do what you can live with. If you're miserable and you can't live with what you're doing? Find something else.