Everything about the GL1000 can really be summed up with the phrase "Better than you'd expect". It's heavy, but carries the weight well. It's not the fastest, but it's closer than you would think. Come to think of it, it takes a lot of the pros of the CB750 (not the best at any one thing, but a lot of really good things all in one package) and takes it farther.
Suspension may be it's weakest area, if I had to pick one. I love the look of my spoke wheels, but I think there was a good reason they got dropped after '77. It can feel a bit "over-engined" for the frame at times, but on the flip side you also have a bike that at times feels like it's got more engine than it needs.
The power curve is a bit unexpected as well. 3500 rpm is a happy cruise speed, and most of your daily driving will take place under 4500. But because all the power is hiding in the top end, if that's all the riding you do, it feels like a bit of a slug. Crank it up above 5000, though? The power delivery literally feels like you hit another gear. With a redline of 7500-8000 (I forget), you get plenty of room to play.
I've taken my 'wing through the Tail of the Dragon before, and plan to head down again in a couple weeks. I'm from farm country Michigan, and I'm not used to curves, so I guarantee I didn't ride that route to the ragged edge of my bike's performance. But that bike handled itself really quite well.
Glad to see you're enjoying yours. They really are a sweetheart of a bike once you dial them in.