The benefits of having a DNP is equipping yourself to be more marketable and adds to your leadership skills. It may not change your rate of pay immediately but it gives you leverage to ask for a raise or negotiate a higher salary. Using your knowledge as a change agent you are qualified to help with cost savings and maintain quality care. I know there are plenty of MSN prepare NP's that can do this as well but it helps when you have the credentials. As was said, it is the terminal degree.
I agree with what Gator said. I am an FNP also, and am working in Internal Medicine which is so much different then my clinical settings when I was in clinical. I would also try to do a hospital rotation just to see the difference. I think in the clinic the focus is on preventive medicine where as in Internal medicine you're dealing with the right now problem and trying to get the patient out of the hospital. I still want to work in a clinic to get my full FNP experience. This is good for a start to get used to different diagnosis and test.
Once you get experience as an RN you know how to treat the patient most of the time example low K+ level, GI bleed, but you have to call and get orders prior to doing it, as a NP as Gater said, you will be giving the orders. Being an RN for 27yrs, definitely has helped me with critical thinking and how to treat my patients