At Coherent Source Service, they were effortless and pure. Rob had a great amp driving them, but I don't remember what it was. The flat-front drivers of the original 7 address a real problem of cone drivers. The sound of the upper driver falls into the cone cavity of the driver(s) beneath, creating a particular hollow congestion which I have identified both sonically and in measurements. The 7 is free from that problem. Even though Jim improved the technical driver performance for the 7.2, Rob and I both found the 7s more musically enjoyable in his small room where we could barely get 8' away.
I am told that Jim was working on the 7.3 after the 3.7, including a refinement of the 3.7/2.7 upper coax, modified to more readily cross over to the 6.5" CS7 lower midrange and CS2.7 - 8" woofer. The 7.3 would certainly have had the flat-star lower drivers, which address that cone cavity problem. Plus each generation of his drivers stood on the shoulders of its predecessors. Imagine that speaker. But, the 7s or 7.2s are pretty good in their own right. If a pair came my way, I could live with either one of them.