So-called "true balanced" circuitry is a misnomer and a red herring. It's more properly called "differential". Given that, it's about as useful to balanced interconnection as it is to unbalanced interconnection. In other words, it really doesn't matter. The reason is that balanced interconnection depends on the common-mode impedances at the inputs or outputs to be matched, or balanced, in order to do its job. That is it --- it doesn't depend on your component's internal circuit topology, nor should it ever.
The reason it should not depend on your internal topology is because the job of a balanced input is to cancel common mode noise at the input, before it gets into the rest of the component --- this is well-known in any electronic design field that's trying to shield against outside noise. One of the worst designs and persistent myths in high-end audio is that you need separate amplification of both balanced signals, because, along with allowing common-mode noise into your component, which is difficult to remove once it's inside, you also end up taking up headroom with the common mode signals that should have been canceled at the input. In effect, you end up paying for twice the components and the design becomes worse.
There are many ways of getting balanced or matched input or output impedances --- active balanced circuitry, transformers, or passive matching. There are advantages and disadvantages to these methods, and which one you use depends on your application. The extra +6dB of voltage gain for some kinds of balanced interconnection is a side effect, and not a primary effect of balanced interconnection.
There are also good reasons to use an internal differential topology, but accommodating balanced inputs or outputs isn't one of them.
The white papers at the Jensen Transformers website gives good explanations, technical and otherwise, of balanced interconnection:http://www.jensentransformers.com
Especially relevant is application note AN-003