Well, the board you are talking about is mixer, but I don't think you can use it as a control surface to control your software's mixer, but maybe that is not your question...

I use a mixer along with my software for several reasons, mainly, to create good headphone mixes, and reduce the latency. I take and split the signal from my mic pres and send one lead to my mixer, and then take the other and send it to the computer to be recorded. I can then create a latency-free headphone mix. I actually can create multiple headphone mixes by using 4 different aux outs on my board to go to 4 separate headphone mix amps. This allows me to give different mixes to different talents that are recording at the same time.

This is just one simple use...there are many, many more that I don't have time to go into right now, but hopefully someone else will chime in here.

Totally agree with D.Helix about monitor mixes etc. but I also find 100mm fader motorised hardware controllers brilliant for playing about with large track count mixes, you can't beat the speed and feel when your just starting out on a new mix and doing it hands on instead of having to mouse it.

I use a Mackie for monitoring, routing various headphone mixes, letting punters hear reverb etc. while recording dry and I use a DDX 3216 as a control surface only which gives me 65 100mm motorised faders in four banks, e.g. bank 1 for bass & up to 15 channels of drums, bank 2 vocs, guitars and so on. I like to use outboard preamps so this setup suits this as well.

Mind you for very small projects I don't usually switch the DDX on, in the right circumstances though a control surface is invaluable and can completely change the feel of a mix or final mixdown.

Cheers, Trace.