The Guzzi is gorgeous but the Hesketh 24 is crass, over 3 times more expensive, probably just as unreliable, and makes half-again as much torque as a Panigale because its engine is larger than that in my Subaru. Plus it’s a Hesketh.
The jugs are much larger, but still a smaller displacement than your bugeye.
It's amazing how ubiquitous S&S has become in these limited-run motorcycles. Arch cycles and even Morgan Motor Company uses S&S engines. They've come a long way since rebuilding Panheads in the '50s. I've only recently become aware of Hesketh Motorcycles, and I admit it's only because of the movie Rush.
The other fun obscure bike is the Münch Mammoth that predated the whole UJM category... 3 years prior to the CB750. Imagine this - it's 1966. The 1965 Volkswagen Type 1 on the market makes 50ps from its flat 4 engine. Enter the Münch Mammoth with 90ps in a motorcycle, in 1966! And it was Deutsche!