Hi Alan, I have owned most and used all mentioned except the BSS DPR504 (I have no opinion on that unit). Listening in the studio solo channel through a $10k pair of Westlake monitors the Aphex 612 or 622 would be my first choice. For live sound the Aphex units or the Drawmer 201 would be worthy of your new APB console. All the others spoken of are toys sonically in my opinion. The Drawmer is the darling of live sound, easy to use, rider friendly, sounds good, actually works, etc etc. The Aphex units are serious precision tools with the VCA operating in class A if I am not mistaken. They were not as popular for live sound because of the $1000+ price tag for 2 channels when new. They are the most sonically transparent analog gates I have ever used and are actually a downward expander which means you can back the ratio down and not just be on or off. I bought a couple more 612's for $125 a piece on eBay a year or two ago. If you decide on one of the older Aphex units you might need to replace the capacitors for a good measure and you are good to go for another 10-15 years. I have not had to on mine yet but I am just saying. By the way if you tire of the APB send it to me or Kemper and we will dump our British boards.