I do most of my work on computer although lately I want to rely more on my Alesis Ion synth as well as add a Dave Smith Instruments Mono Evolver Keyboard. So I'm looking not only at a front-end compressor unit that will feed into my Mackie Onyx Satellite recording interface, but also act as a master bus compressor to bring out the final 2-track mixdown, add a little compression and warmth, and take it back into the computer for digital mastering via Waves plugins or Izotope Ozone. I guess I'm basically looking for high quality subtle compression and analog warmth going into my computer and out. I can't decide between the Focusrite Penta, ART Pro VLA or the FMR RNLA. I'd like to keep it under $500. Any help would be greatly appreciated. Are there any other units that would be good at doing this that I haven't mentioned? I used to have an HHB Fat-Man tube compressor which I regret selling, but I was out of work at the time. It was great for fattening up individual tracks, but not for the final mix. It wasn't clean enough for that.