well, it depends.
First off, I am glad you got a JD. I think they are one of the most beautiful freshwater fish there are.
I have a larger 11" Male JD that is very aggressive. When I have had him with tankmates, they have had to be smaller and quicker. He did pretty good with a couple of (Short Bodied) Convicts that I have for about a year. Now he is in a 55 gallon with a few african cichlids, the african cichlids are doing fine; the JD doesn't even bother them. But if I put him in with another larger fish like an RD or an Oscar, it has been trouble.
My JD was raised in a tank with another JD, a Lutino tiger Oscar that got very large and some other random cichlids that my brother had. I inherited my JD from my brother when he moved. So the JD did okay with the tankmates he had from a juvinile. but when I got him and put him in my tank, he didn't like any competing fish. So you may want to get any tankmates for him now to grow with.
Here is a pic my current JD.