Well, the Kawasaki triples were noted for having handling envelopes that resembled swiss cheese, what with all the holes in them. The Z-1’s handling was not noted as being especially good either - in fact, poor handling was a Kawa trademark well into the 80s and 90s, culminating in the ZX900 disaster of a bike. The H2 750 two-smoke was known as a widowmaker. Having ridden one, I would agree. Handling on that thing best described as “frightening”.
The Suzuki GS series is known to be truckish in general. Don’t recall anything really bad about their handling, but nothing great, either.
Honda generally had their handling envelopes together back in that era, when so many others from the US and Japan, including Harley, really didn’t. The only exception among the 70s machines was the original CBX, which had a swingarm that was a tad short and tended to go into weaves at high speed. Though disturbing, it never caused a crash, and Honda fixed the problems shortly thereafter.
Personally, I really liked my 75 Honda CB750 and put a ton of miles on it. I didn’t like my roommate’s Z-1R very much - again, holes in the envelope. Liked his KZ750 twin even less.
The Honda CBR1000RR looks appealing.
I rode the 1984 Kawa 750 Turbo for 18 months