Rather than starting a new thread I want to ask some basic questions about mixing.

I am currently using a Dual channel Sabertooth with built in mixing which is brilliant but more expensive than other options and if I build more bots I need to understand my options.
I see various people talking about mixing on the controller to varying degrees of success.
I also see some comments online about mixer units and some talking about v-tail like this or this or those Tramp mentions here

If I am right then this model may be exactly what is needed to solve the original question in the thread - here

Anyone have experience plug in mixers?
Advantages disadvantages of in RC mixing vs in TX mixing

Thanks