I sold the last of my GS1000's last year to a friend who owns over 40, including some historic race bikes.
Without doubt, they were the best engineered Japanese motorcycle of the 1970's, with the power and strength of the Kawasaki Z1 engine (that Suzuki "borrowed" their engine design from) but with a far superior chassis, which left Z1's wobbling and wallowing in their wake.
I owned a couple of GS1000S, ("Wes Cooley Replica's") a couple of GS1000E's (standard model) and one GS1000G. (shaft drive touring model that was actually quicker than the "S") I was also given a GS1000 based drag bike (which was what started off my interest in them in 1995) which produced 140 BHP at the back wheel and ran sub 10 second quarters.
Of course I had no interest in drag racing, so I pulled the engine and installed it in a stock GS1000E that I bought with a blown engine, and had lots of fun with it until I sold it to a guy in Britain. It was scary fun, and even though GS1000's are superb handlers compared to any other Jap bike of the era, that amount of power was testing the stock chassis' limits.
Some of the bikes I've got in my garage will do anything that the old GS will do but better, but they're from another era, and by then the old GS1000 had morphed into the GSXR1100, which of course was another very capable bike as well. Cheers, Terry.