Mix Live Sound in a DAW?
Disclaimer: I do have a license for Reaper and I have recorded a couple of shows but I have never even tried to mix down the recordings much less attempted to use a DAW to mix a live event. The arguments that I present are based on things that I have heard and my familiarity with the virtual live mixing of sound through my years of using a SAC system.
The DAW (Digital Audio Workstation) has all but taken over the recording industry. DAWs allow the artist to record more easily than ever before and at a lower cost. DAWs are used almost universally in the production of recorded music from the individual artist and small demo/project studio to the top of the line full recording studios. Because of the general familiarity with the software some feel that they should be able to mix their live performances in their favorite DAW.
DAW software is specialized recording software. The features of the software are designed to make recorded music production fast and relatively easy. The studio and live venue are far different worlds. It is always a good idea to use the best tool for any job. While DAW software is a good tool in the studio it may not be the best tool to use if trying to do live sound mixing in the box.
Latency is not much of a problem when mixing in the studio but becomes quite important when doing live sound. DAW software is generally not optimized for good low latency performance. Layout, navigation and features are optimized for the recording workflow in a DAW but may not be the best for a live performance. DAW software is designed for the production of music in the recording studio.
Software specifically designed for the requirements of the virtual mixing of live sound would, almost certainly, be a better choice to mix a live performance. With features and navigation designed to allow the speed and quality necessary for the production of live sound the LAW (Live Audio Workstation) has got to be a better choice. Depending on the specific situation DAW software may be useable but not nearly as convenient to use as software designed to do the job at hand.