I certainly hope they've improved since I heard those KG's. I heard the corner-horn, the cornwall or something like that... and the KG was supposed to be the 'new improved' one. I bought the 2.5 and the 1.5 I believe. They were mated to an Onkyo integrated SS amp... that was known to be bright and harsh to begin with.. I know it wasn't a good combo for accurate listening but, boy was it loud. And in the mid-90's that's what I wanted. Every system I've built past that I've still wanted a 'lively' sound but little by little I keep working back towards dead neutral and leaning to warm... but not too warm or 'sweet'.. or colored...
So, if the new RB75's are very neutral and don't sound like a horn and sound like music, that'd be a good improvement. I just don't care for that horn sound. However, I haven't listened to horns in a long time... maybe I'll check 'em out ...