Diverting Valve vs. Mixing Valve

[blutfort]

I've spent the last hour explaining the differences between a mixing valve and a diverting valve to a new guy here in the shop.
One question that came up is why mixing valve vs. diverting valve? I was always told that the valve had a better control characteristic when piped in the mixing configuration. I guess the question that needs to be asked is why? Does that answer still apply in the world of flow control linearizing discs?
Once we have a few people chime in this might be a good topic to compile and add to the FAQ area.

Thanks!