Should I switch to a preamp with balanced outputs

Keep what you currently have. You are very happy and enjoy the sound, that is the most important criteria. I see no reason to pursue balanced.

If you already have all the gear and it sounds good the way it is, leave it alone. Just because you change to a balanced preamp doesn't mean the only changes you will hear are from the balanced operation. It will still be a different preamp and will most likely sound completely different than you CJ, balanced or no. Also, its not very likely that you will be able to get a preamp that sounds at least as good, if not better than your CJ for $700.

I've used balanced mic cables in pro audio for centuries but for hifi isn't it a gear specific thing? I read reviews where the reviewer finds the balanced output (or input) sounds better sometimes, but others show no difference. Long cables...balanced of course...I use short balanced cables mostly because I like the "canon plug" connectors, but my power amp input ties two pins together anyway thus somewhat obviating the benefit of the balanced cable from my ACTUALLY balanced preamp, so I guess you gotta try variations. If there's no noise I figure you're doing fine.

Skipper320 hi, I believe you want to know is there an advantage using balanced (xlr) over single ended (rca)?

The short answer is NO, if the interconnects are around 5mt or under, and not passing next to any heavy noise noise generating equipment EG: a switchmode transformer.

The only time (xlr) can have an advantage over rca is "noise" if the interconnects are >10mt long

Even then, sadly many poweramps and preamps I've seen, use an opamp to create a balanced inputs or outputs, only to be really a single ended in design, these definitely sound better via their single ended inputs or outputs because all you are hearing via the balanced, is an opamp in the single path before the discrete rca circuit.
And I've seen this on some high end equipment!!!!!!

Cheers George

Most great sounding pre amps do not even have Balanced connections. I'm not sure what the Question is? XLR connections are really meant for long cable runs, that's why its used in professional studio and stage environments. All balanced does is provide a third wire as a complete separate ground as well as providing 2 lanes for Positive and Negative to travel. Un balanced design is simpler and that's why many tube preamp designers avoid the more complex design of balanced. I have used both and I have heard no significant sonic benefit from one over the other. SO if you love the sound of your CJ ...I would KEEP it! at this point things get different not always better.