These are my daily driver. I didn’t realize anyone had inventory left on them as they have moved to the much talked about RP 600M. The biggest difference in the listens that I have had is they do something on the new model to temper the efficiency just a touch (the 95-96 db rating has been disputed on the 600M on many forums)… The newer tweeter has a slightly different vent that makes it ever so more slightly laid back. If you don’t mind your horn stand mount ultra efficient speakers in black I don’t see a very compelling reason to spend more on the 600M. I use these daily, they have a wonderful energetic character to them. Can run off pretty much any amp you have laying around, but they will definitely benefit from either a bass boost, or ideally a nicely blended subwoofer. This is a fantastic deal while it lasts.