The H2 was a weapon, probably quicker than the Z1, but as Mick has attested about his experience on H1's, they were pretty awful handlers.
We called them the "Widowmaker" here, althought to be honest, I don't know anyone who was killed on one, but several of my friends died on CB750's and Z1's, so maybe we had a false sense of security about these bikes because they handled marginally better?
In 1979, I was bike less. I'd sold my F0 (POS) and bought a car. A friend of mine was keen to buy a bike, so I took him shopping, and we bought a 1976 Suzuki GT750M. (or it might have been an L, I don't remember) He took it for a ride, #$%* his pants, and so we swapped, I took the Suzuki, and he took my Ford. We were both happy.
I rode the Suzy the 200 miles to my folks place in the country one weekend. I was on the old Mulgrave (now Monash) Freeway, tooling along at around 70 MPH, when a guy on a H2 with 3 separate expansion chambers screamed past. I chased him, and sat on his backside @ 100 MPH, but he easily pulled away from me, and I lost him in a haze of blue 2 stroke smoke.
I caught up again with him in a little place called Yarragon, he was on the side of the road doing some work on his bike, so I pulled in to say "G'Day" and have a look at his bike. He said G'Day back, and continued replacing his spark plugs. he was wearing an old army "Greatcoat" (we didn't have no fancy motorcycle clothing back in those days) and had a dozen or so spark plugs in his pockets, and he'd just keep cleaning them and swapping them as they fouled up. His bike was amazing, it was virtually a race bike, and he told me that it actually handled as well. It had Koni shocks, and the frame was braced, it had a multi-adjustable steering damper and Pirelli tires, and he'd braced the frame up too.
We rode together to Sale, where he peeled off, and I continued on to Bairnsdale. (my home town) In the 200 mile ride, I'd had to fill the tank 3 times, their fuel economy was pretty bad when ridden responsibly, and a hell of a lot worse when riding them at 10/10ths. Great fun though. The GT750 was about as quick as a CB750, but was no match for a H2, even a stocker was probably 100 pounds lighter, and much quicker. Cheers, Terry.