Noise reduction - pros and cons?

I've got the baby digital over here - I've got an E-300. It does what I need it to do, so I'm happy. I haven't used the noise reduction feature yet, but may need to. Are there any issues I should be concerned about? (I'm clueless, yes, that's why I'm here.) Does it detract from the image in any way?

It's digital - test it! One of the great things about digital camera is you can quickly and easily test to find out what a given feature or situation is going to produce. A couple of potential issues with noise reduction are loss of sharpness and increased processing time. If you're working slowly than the processing time won't be an issue. But loss of sharpness might be. So test it to find out. There are a few methods for reducing noise. I believe the Olympus in-camera noise reduction maps the noise pattern of an image and then attempts to remove the noise. That's a pretty good technique. But test it to make sure the results will be acceptable for you. No need to wait until you're actually shooting the job.