If you are going into a consumer product then it's probably looking for -10.
If you have a 'pro' mixer then it's gonna want to be fed +4.

Pros and cons?

Depends on the quality of the inputs, really.
A Neve has far and away better sound quality than a Realistic mic mixer...
Both can boost a -10 signal, but which do you think will sound worse once your done turning the pot?

I always go for the +4 - Unity gain - 1.23 Vrms, ya know? ...

Oops, also, the difference between balanced and unbalanced lines:

Unbalanced lines feed the signal from point A to point B with no change down the line (in laymans terms), any dirt picked up (hum, degradation) gets amplified at your preamp.

Balanced signals start off by flipping pin two and three out of phase, shooting down the line, and flipping the pins back into phase at the input - the result cancels any hum or other 'dirt' that gets into the line on it's trip, as well as allowing for much longer runs at lower voltage than unbalanced - can you dig it?

I can dig it.

P.S.

I'm using a Neumann TLM103 into an aphex230 into an old 1983 panasonic ramsa board--it's a monster, but I like it.

So -10 or +4?

Thanks,

--Stephen

Hey man, Ramsa's are rockin'!

They made, at one time, one of the most often used speaker cabinets where I work.

If you hit it with +4 and it clips, then switch it to -10!

What flavor of Ramsa is it (model, I mean)?

Panasonic Ramsa WR-8724