This is a really subjective question. If you like playing on a 5 string bass then by all means get a 5 string bass. You might even want to try a 6 string before making that decision. Use however many strings you are comfortable with. There really isn't an absolute answer.
Any number of strings is good for any kind of music. In any standard configurations, no matter if you're playing 4, 5, or 6 string basses, four of those strings will be the same. The style of music generally is about your tone not how many strings you have.
One obvious advantage of having more strings is a greater range, one that's greater without as much movement or a different setup on a four string, rather. One thing to consider though, is with that greater range whatever your current amp set up is may or may not accommodate it. Along with getting a new bass you might have to get a new amp/cabinet on top of that.
An up/down sides to having more strings is usually they'll be spaced closer together than a four string. They also tend to have much wider necks but not always which leads back to the first statement. This is where a lot of subjectiveness comes in. Some people find it easier, some don't.