ACR Ref 110 - Regular feet or couplers?

If they are rubber feet I would try something else. Martin Colloms uses this stand
[ or another model] and uses SR MIGs under his Ref 5 pre and other gear. I use them also on my quite different stand. Stringreen is right that they all sound different but I have found that they all sound better than stock rubber feet.

Actually, all that stuff changes the sound differently. You should use your ears and decide which if any of these things is your preferance. What one person may like with his/her cables, electronics, speakers, room, etc. you may think of differently. The joy of this hobby is to make it your pleasure.