I wish that I had the knowledge that some of the posters around here do, but let me offer my humble input:

I have heard the difference between balanced and unbalanced connections between preamp and amp, and WOW! The balanced connections produced a complete lack of hiss/hum that was present with the unbalanced connections. The amount of hiss/hum present with unbalanced was not unusual for midfi equipment, but when the low amount of hiss/hum was GONE with the balanced connections, the music sounded so much more lively and wonderful. I have to say that any nth-order distortion effect problems that soundhound mentioned, were completely overwhelmed by the positive improvement to the music that the "totally black" background and dramatically lowered noise floor offered.

I wish my pre/pro had balanced outs. In fact, if it did, I would probably consider using it with high-quality active biamped monitor speakers, and thus avoid using any external amplifier at all! Can anyone here offer any advice about that idea? I am still a relative newbie to all this stuff, so I can't (and don't wish to) argue with soundhound or others about the electronic specifics - I can only rely on my own ears here!

I am very glad to see that Outlaw is offering balanced outs on their new pre/pro, and this is actually a major selling point for me (I think...)