I have used multi-band compressers and there's a good one that comes with Reaper but I like to try and track Guitars/Bass etc so they need as little mixer treatment as I can and therefore use one of the other great VSTs that comes with Reaper called,"ReaComp".In saying that I usually EQ and Comp the guitars and bass quite often even if it's only subtle.The compressor in Podfarm is ok but too limited in most cases.