"Playing The Field"

Is it safer? Not really. Even if condoms are used correctly a 110% of the time there is always the risk of an accident. Although accidents are rare they can still happen. I slept around quite a bit as a teen and into my early 20's, I was aware of the risks and did the best that I could to keep myself protected. Condoms/dental dams were used for vaginal, anal and oral sex. I also got tested regularly.

As to being more enjoyable, that I am going to say would depend on the person. Many people have emotional connections to sex while others have purely a physical one. These people tend to need there to be an emotional attraction, trust, etc to engage in sexual activities with a partner. People like that can find it difficult to engage in casual sex with multiple people. While they be able to enjoy the actual sex it may seem lacking something or even cheap to them.