Unlike Altec A5 and A7 series which were designed for theatre use, Altec's paired with 604 drivers are know for their prowess in recording studios... or domestic use in the case of Model 17 and the less common Model 18.
You should pose your question on the HiFi Haven forum, as I've found the members of that forum to be the most knowledgeable when in comes to horn speakers, especially all things Altec.
I own Altec Model 19's, which are supposedly somewhat similar to A7's but intended for domestic application. They have a big, dynamic, live, airy sound unlike anything I've heard from previous box speakers I've owned (Dynaudio Confidence C2 & C4... and Harbeth flagship 40 series). They need a large room to sound good, with considerable distance between speakers and the listener... I sit about 12 feet back. I've been toying with buying 604's paired with a 620 cabinet down the road, as many Altec aficionado's seem to like them a lot... but some prefer the large A5 and A7 series... but those definitely need a large room and have little to no WAF.