Union experience?

Has anyone here had experience being part of a union? I'm interviewing for a role at a cultural organization where staff recently unionized. I've never been part of a union and worry about how it would impact my ability to negotiate salary and benefits. (It doesn't help that the top of the salary range posted for the role is lower than my current salary, although not surprising, since the job title is also lower than my current title.) Any thoughts are welcome.